Manual Refrigerator Diagnostic Service Manual
Contents
1. RM2801 2934901097 58 2007419217 325 120 0173742016 27 44 RM2801 17 9 RM2802 RM2803 2934901097 58 2007419217 325 120 0173742016 27 44 RM2804 2934903994 58 2007419217 325 120 0173742016 27 44 RM2804 215 412 0173757014 p expo 17 9 RM3500 Imus 39 2007419159 2007419159 185 120 0173738063 115 80 __ RM3500 17512 0173739038 _ RM3501 2934701091 39 2007419159 185 120 0173738063 15 80 __ RM3501 UE ME NIMM 14 6 RM3600 2934801099 53 2007419191 295 120 0173754045 25 48 RM3600 D C esos owarssoe ____ 208 RM3601 RM3601 215112 1131879223 RM3604 Immo 53 zm 295 120 0173754045 2 5 48 T RM3604 215 12 0173757022 1 4 17 9 RM3800 58 2007419217 325 120 0173742081 n Mo www vwT25camper info a useful site for Models that use brass heating elements approximately 3 4 dns diametersars of VW T25 Vanagon campers Bulletin 28 continued Cooling Unit Orifice Size Heater Element Specs A C Part No amp Part No Watt Volts Part No Amps Lazsne 0173743030 2934901097 58 200741921 325 120 0173742081 Model No T ee 0179750001 rs hl ocu e tae aha ha 21512 0173757002 RM4801 Models that use brass heating elements approximately 3 4 in diameter NOT2. 54 222 654 D 85d2 9929375042 7 1 2922441016 65 1202 2922372020 54 222 54 1 8512 2929375042 63 190 71 2942312121 2929375042 71 225 120 0170679013 19 63 N A 225 120 0173074014 19 63 __ 2922034000 65 120 12 2922372020 5 4 7 9 __________________ 5 2 0173723016 4 3 95 1204 2 01797090093 01118 olo ec 0 4382 0ir3729018 pl c i 860 25 221 201797090001 522221 E _ ql 18042 0173724014 j 193 Ooo y 4692 0173724044 d 133 _ __ _________ 159 120 12 0173709007 2 1125 1 150 120 12 0173709007 13 92 125 2752 38003680031 229 7 1 85 12 2929375042 74 2902540059 95 12 ____ 2902192106 79 9283171008 9281 152000 9282740010 4 2901860010 7 9 19282743005 4 2901860010 95 120 12 2901943000 7 9 19282761000 2902540075 95 12 2902192125 x8 www vwT25camper info a useful site for e Models that use brass heating elements approximately 3 4 in diameter ers of VW T25 T3 D 9 14 et Vanagon campers Bulletin 28 continued Cooling Unit Orifice Size Heater Element Specs A C OHMs DC Model No Part No amp Part No Watt Volts Part No Amps Resistance AMPS RM360 361 REN 9000 2007419134 150 120 0173734013 zr RM360 3
3. 90 or more even a minor restriction will cause overheating of the cooling unit and the cooling process will slow down or stop ONE LASTCHECK a If the previously mentioned test was performed in air temperatures above 90 and the temperature in the refrigerator is above the acceptable ranges it may indicate a restricted air flow To make sure there is no problem with the venting system repeat the perfor mance test with the refrigerator removed from its installed location and placed on the floor or in your service shop If the second test indicates satisfactory performance re check the venting and installation PART OTHER CAUSES FOR LOSS OF COOLING If the previously mentioned performance test shows that the refrigerator is working satisfac torily and the customer still experiences loss of cooling the following items need to be considered 1 Make sure the customer is using the refriger ator properly The cooling capacity of the absorption refrigerator is usually much lower than the refrigerator the customer has in his home so the customer should be advised to follow the instructions for proper use in his Owner s Manual A Start the refrigerator the day before it is to be filled with food B When the refrigerator is being filled when preparing for a trip the food should be pre cooled and frozen foods should be pre frozen before placing them in the refrigerator Ice making should be avoided until the refri
4. Level 2 Air Flow Ventilation 3 Heat www vwT25camper info a useful site for enthusiasts and owners of VW 25 Vanagon campers 25 Three things st be remembered when diagnosing a cooling unit First circulation within the cool ing unit is totally gravitational This means proper leveling is important Second heat created to boil the ammonia now has to be dis sipated into the surrounding air Heat from the absorber and condenser must also be dissipated so as to cool the ammonia sufficiently Third proper heat application at the boiler section 26 When diagnosing a E unit remember this is the only part we cannot field check with test equipment yet it is the simplest and quickest part to diagnose 27 After the unit T 2 operating approximately one hour carefully touch the unit at the boiler box and the absorber area These areas should be approximately the same temperature regardless of the ambient temperature Equal heat between the boiler and the absorber indicates the fluid circulation within the unit is good THE ABSORPTION SYSTEM WATER SEPARATOR CONDENSER PUMP GAS S SS TEMPERATURE EXCHANGER ul n ABSORBER s M t ABSORBER VESSEL BOILER LIQUID TEMPERATURE zm EXCHANGER DIAGNOSING THE COOLING UNIT EVEN TEMPERATURE GOOD CIRCULATION www vwT25camper info a useful site for en
5. contact to the liquid ammonia solution in the absorber vessel the ammonia is absorbed into the liquid solution allowing the hydrogen vapor to rise up through the absorber coils After this absorption process the vapor consists of mostly hydrogen with some traces of ammonia 14 To remove the ES amounts of ammonia vapor still present in the hydrogen a continuous flow of weak ammonia solution is fed by gravity to the top of the absorber coil from the boiler As this weak ammonia solution flows downward through the absorber it absorbs the ammonia vapor from the mixture allowing the hydrogen vapor to rise through the absorber coil and return to the evaporator With the hydrogen returned to the evaporator and the ammonia remixed into solution in the absorber vessel the cooling process can continue 15 Now that we have basic understanding of proper cooling unit flow and operation let s take a step by step look at the three require ments for proper cooling unit operation Please note it is essential that these three requirements be diagnosed before attempting to diagnose the cooling unit A problem with leveling heat input or ventilation may lead you to think that the cooling unit is faulty when actually it is not This causes an increased expense to you the customer and valuable shop time is wasted because of incorrect diagnosis By following and checking the three unit requirements costly diagnostic errors can be eliminat
6. freezer compartment The coach should then be positioned so that at least 3 4 of the bubble is within the required mark while the refrigerator is in operation REMEMBER Failure to property level a square boilerbox can result in a lack ofcooling or permanent damage to the coding unit When the vehicle is moving leveling is not critical as the rolling and pitching movement of the RV will keep the solution in motion preventing the solution from accumulating in the piping THREE REQUIREMENTS FOR PROPER OPERATION 1 Level REFRIGERATOR IS TO BE LEVEL LEVELS www vwT25camper info a useful site for enthusiasts and owners of VW 25 T3 Vanagon campers In recent years Dometic has engineered a new type of cooling unit that utilizes an improved siphon pump tube design which drastically reduces the possibility of permanent damage to the coils if operated in an out of level condition or too much heat is generated at the boiler section As we can see from this drawing the siphon pump tube is enclosed in the design and is surrounded by a weak ammonia solution which will protect the pump tube from abnor mally over heating This type of unit however does not eliminate the need for proper leveling The unit still requires gravitational flow to provide the proper cooling process and if leveling is outside the necessary limits cooling will dramatically slow down or stop completely Th
7. heating elements completely back into the pocket Reconnect burner assembly to chimney and replace cover FIG G2 A SEALING PERMAGUM Sealing Tape B THERMAL MASTIC FIG G3 enthusiasts andBaamers of VW 25 Vanagon campers Before You Change That Cooling Unit PART PROPER DIAGNOSIS Cooling units are sometimes diagnosed as being defective when the actual problem is something else Cooling units are expensive to replace so it is important to make the correct diagnosis By using the proper test procedures you can eliminate all other possibilities before condemning the cooling unit Any time the cooling unit is a possible suspect use the following step by step procedure before replacing it A PRELIMINARY CHECKS l Check for an ammonia smell around the cooling unit and inside the refrigerator This could indicate a possible refrigerant leak Check for any deposits of yellow powder on the tubing which will sometimes form around the area of a leak NOTE A yellow deposit in the area of the fill valve could be due to splashing of refrigerant during manufacture and would not indicate a leak 2 Determine if the refrigerator works on one heat source but not another by testing it in the alternate modes Also ask the customer if he gets better cooling results from one energy source than another If this is true it indicates the problem is NOT in the cooling unit 3 sure the
8. slow spark causing the light to blink A lesser distance will create a fast spark that may not light the burner SPARK GAP Electrode gt www vwT25camper info a useful site for enthusiasts and owners of VW 25 T3 Vanagon campers The El rical S e Electrical System ELECTRICAL SYSTEM 64 The electrical system consists of a combination switch assembly heating element and thermostat The quickest method of diagnosing the electrical system would be testing for continuity of components 65 Following the wiring diagram the component that does not show continuity would be suspect 66 The selector switch should be checked for SWITCH ASSEMBLY continuity in the following manner Remove all wires from the assembly Continuity should code Mode exist between terminals 1 and A and 2 and 2A for the DC mode When the switch is put in the gas mode you should have continuity between 3 and 3A if the unit has an igniter reigniter For the AC mode you should have continuity between 4L and 4A and 5N and 5A If you find lack of continuity in any mode when making these checks the switch is defective and should be replaced Shaft Assembly DC Mode Gas A C Mode 25 8 a useful site for enthusiasts and owners of VW 25 Vanagon campers 67 Before an appliance can be sold to a recrea tional vehicle manufacturer it must be
9. tested and approved by a nationally recognized testing laboratory for the specific end use intended All Dometic refrigerators used in recreational vehicles have received this certifica tion 68 If you require additional service assistance on the basic requirements for the cooling unit operation or the manual refrigeration please refer to the diagnostic manual For additional technical service assistance contact the Technical Service Department at 219 463 4858 You are an essential part of a team that con tributes greatly to the successful future of the RV industry your dealership and Dometic Thank you for participating in the training program www vwT25camper info a useful site for enthusiasts and owness of VW 25 T3 Vanagon campers NOTES www vwT25camper info a useful site for enthusiasts and of VW 25 Vanagon campers 12 Glossary of Terms MANUAL REFRIGERATION ABSORBER Section of the cooling unit where the hydrogen and ammonia vapor are intermixed in the absorber Ammonia vapor returns to solution and the hydrogen returns to the evaporator BOILER Section of the cooling unit where heat is applied This is where the ammonia is partially separated from the water BY PASS SCREW Small brass screw located on any Dometic gas thermostat that regulates gas flow in the low flame mode There are three common sizes of this screw S 17 350 BTU S
10. thermostat capillary tube and pull out 1 FIG E2 5 Complete removal of cooling unit 6 Remove evaporator fins and shelf 2 FIG E2 INSTALL REPLACEMENT COOLING UNIT 1 Apply thermal mastic on the evaporator coil B FIG E2 2 Install evaporator fins and shelf FIG E2 3 Apply sealing permagum sealing tape on window insulation A FIG E2 4 Reinstall capillary tube into proper position FIG E2 5 Tighten screws securely to obtain proper sealing 6 Reconnect burner assembly to chimney and replace cover FIG El www vwT25camper info the heating elements completely back enthusiasts and owaers of VAffeodberpecket FIG ED Vanagon campers Bulletin R55 7A continued FIG El F Category 6 RM75 RM76 RM77 REMOVAL OF COOLING UNIT 1 Remove burner protection cover and remove burner from chimney FIG Fl 2 Remove heaters from boiler case FIG FD Remove evaporator screws FIG F2 3 Remove two 2 screws holding clamp for thermostat capillary tube Pull capillary tube out gently FIG F2 5 Remove ten 10 screws holding unit from rear FIG 6 Pull out on cooling unit and remove B DE gt THERMAL ze AE 82 6 MASTIC put 5 227 gt xml A Me dk SEALING PERMAGUM w Sealing Tape FIG E2 FIG F2 INSTALL REPLACEMENT COOLING UNIT l Trim the Styrofoam portion of the cooling unit if it does not go freely into th
11. units purchased from Dometic for out of warranty Dometic refrigerators only for 35 00 RC 150 RM 215 RM 361 RM 66 RM 663 RM 763 RAK 100 RM 182 RM 235 RM 46 RM 66E RM 76 RM 100 RAK 1302 RM 190 RM 36C RM 46E RM 66F RM 77 RM 13 0 RA 1300 RM 211 RM 36E RM 460 RM 660 RM 760 RM 1303 RA 1302 RM 2118 RM 360 RM 461 RM 661 RM 761 RA 100 RC 65 All Dometic cooling units for Dometic refrigerators manufactured prior to these models will no longer qualify for our Dometicare coverage CROSS REFERENCE OF REFRIGERATORS MANUFACTURED BY A B ELECTROLUX HADCO DOMETIC GE DOMETIC HR 2 same as RM 24 TG3 S OB same as RM 36 HR 3 same as RM 36C TG4 S OB same as RM 45 HR 4 same as RM 460 TG5 S OB same as RM 60 HR 6 same as RM 66D HR 7 same as RM 760 MAGIC CHEF DOM ETIC INSTAMATIC DOMETIC MKM same as M 28 IM 2 same as RM 211 MKM 110 same as M 40 IM 3 same as Hhl 36E MKM 150 same as M 52 IM 4 same as Rhl 46E R 82 83 84 85 86 same as RM 75 IM 6 same as 66 R 87 same as RM 77 IM 7 same as RM 77 R 88 same as RM 760 IM 10 same as RM 100 www vwT25camper info a useful site for enthusiasts and owners of VW 25 Vanagon campers REFRIGERATOR BULLETIN NOVEMBER 1980 37 HEATING ELEMENTS 360 460 660 760 Previous literature covering the following models lists the wattage of 110 volt heading elements as follows RM360 120 watts RM460 135 watts RM660 175 watts RM760 250 watts The ratings that are actually stamped on the replacem
12. 0 RM76 1 RM1301 RM2800 RM3800 REMOVAL OF COOLING UNIT 1 Remove screw holding clamp for capillary tube Pull capillary tube out gently and place aside FIG Bl a RM3600 RM3800 FIG B4 Remove heater s from boiler case FIG Bl Disconnect burner from chimney FIG B2 and B3 a RM2600 RM2800 FIG B3 Vanagon campers CA Remove evaporator screws FIG B4 Remove screws holding unit from rear FIG Cut tape holding plate FIG Apply leverage as shown and pull unit out FIG WOOD BLOCK PROTECTION FIG 84 INSTALL REPLACEMENT COOLING UNIT l Trim the Styrofoam portion of the cooling unit if it does not go freely into the RM3Q00 8800 per info a enthusiasts andy gwners of VW 25 T3 Bulletin R55 7A continued 2 3 Apply sealing permagum sealing tape on mounting plate A FIG B5 Apply thermal mastic on the evaporator coil B FIG B5 4 Tighten screws securely to obtain proper contact between the evaporator coil and evaporator flange otherwise improper cabinet performance may result 5 Install the heater element completely back into pocket and plug in 6 Reinstall capillary tube into proper position RM100 RM2600 amp RM2800 will clamp to cooling flange FIG B4 b RM760 RM761 amp RM763 will extend into retainer tube approximately 31 FIG Bl c RM1300 RM1301 RM1303 will ex
13. 14 325 BTU S 1 1 300 BTU Found GAd amp BLECTRIC uTHERM STATt Dometic m a n u a l refrigerators this device is held in place with 0 ring seals in the gas line and replaces separate electric and LP gas thermostat controls On the LP gas mode full line pressure is directed through the thermostat to the burner until the thermostat senses that the refrigerator cabinet has reached proper cooling temperature At that rime an internal valve closes and redirects the gas flow through the by pass screw This reduces the amount of LP gas going to the burner assembly The gas flow remains in this by pass mode until the thermostat senses that the refrigerator cabinet needs more cooling Again the thermostat directs the LP gas flow through the thermostat at full line pressure until the cabinet temperature is sufficient On the electric mode the internal mechanism breaks contact continuity when adequate cabinet temperature has been reached CONDENSER Section of the cooling unit that cools the ammonia vapor into ammonia liquid COOLING UNIT Self contained hermetically sealed set of steel coils where the refrigeration process takes place The chemicals involved in the cooling process include hydrogen ammonia water and a rust inhibiting agent CUT OFF VALVE Shut Off Valve Valve where the incoming propane supply is attached This valve is direct coupled to the selector switch by means of a steel clip When the selector switch is turned to the e
14. 61 22 1120 12 0173735010 10 4 RM460 461 283359009 ag 2007419159 160 120 13 e2 RM460 461 125 120 2 0173735010 1 0 120 dg m 4 RM660 661 660 661 pere eee 14 6 RM663 663 222222117542 04 3 38020 212 71345 RM760 761 RM760 761 sag SF 20 8 RM763 28519001 5 2007419191 268120 0173740 4 125 48 RM763 2125042 0173741020 12058 8 1300 1301 ES ERN TIU 7 tar a aT RM1300 1301 uz Eia ____ 22 9 RM1303 ss 202125 gp 22 RM1303 HR d Dr RM2150 a oe eem 7 9 RM2190 2904377005 2902540059 9512 2902192108 179 RM2192 RM2192 oz eo 41952 29021921295 9 RM2200A 7 9 RM2201 2904586019 F 2902540059 95 12 12902192125 79 RM2300 RM2300 1 112512042 10173735010 10 120 104 RM2301 RM2400 RM2400 1125H20412 10173735040 1 0 120 1104 RM2401 9283359009 39 2007419159 160 120 01737756016 13 92 ___ RM2401 E Lu e jouemsoo ym 10 4 RM2500 RM2500 ee tree ovaries Tt 14 6 RM2501 RM2501 ae fornia TT 14 6 RM2600 RM2601 RM2602 RM2603 HERE E CL TEE RM2604 2934803996 53 2007419191 295 120 0173754011 25 48 RM2604 UEM 222145122224 ousrsmua REE 17 9 RM2800 2934901097 58 2007419217 325 120 0173742016 27 44
15. ATOR The sealed combustion unit contains a mixture of ammonia water and a rust inhibiting agent After this solution is introduced into the coils this unit is ae pressurized with hydrogen gas When TEMPERATURE this system is in operation the am EXCHANGER monia vaporizes in the hydrogen atmo sphere and absorbs heat from inside ABSORBER the refrigerator m t ABSORBER VESSEL LIQUID ln TEMPERATURE EXCHANGER www vwT25camper info useful site for enthusiasts and owners of VW T25 T3 Vanagon campers PUMP BOILER i The cooling unit parts that accomplish this PUMP cooling or heat extraction process include the Boiler or Generator BOILER WATER Condenser GAS TEMPERATURE EXCHANGER Evaporator EVAPORATOR yD ine www vwT25campet info a useful site for enthusiasts and owners of VW T25 Vanagon campers 6 7 Absorber 8 Because the self contained cooling unit does not utilize an electric compressor or pump the cooling coils can be oper ated from a variety of heat sources LP gas 120 volts AC and 12 volts DC heating elements are the most com monly used heat sources for recreation al vehicle applications Before this cooling system can properly extract heat from the cabinet of the refrigerator three requirements for prop er refrigerator operation must b
16. DOMETIC Dometic MANUAL REFRIGERATOR DIAGNOSTIC SERVICE MANUAL The Dometic Corporation Corporate Office 2320 Industrial Parkway Elkhart IN 46515 219 295 5228 Warranty 205 E Fenn St Department LaGrange IN 46761 219 463 2191 Technical Services 509 S Poplar St Department LaGrange IN 46761 219 463 4858 www vwT25camper info a useful site for 051286 8 89 enthusiasts and Owners of VW 25 Vanagon campers NOTES www vwT25camper info a useful site for enthusiasts and owners of VW 25 T3 Vanagon campers D 2 MANUAL REFRIGERATOR DIAGNOSTIC SERVICE MANUAL Table of Contents Page Diagnostic Flow Charts No Operation D 4 No 120V AC Operation D 4 2 No Gas Operation Piezo Igniter JE D 4 3 No Gas Operation Automatic Reigniter D 4 4 Operation and Diagnosis Dometic Manual Refrigerators D 6 1 Glossary of Terms D 8 Service Bulletins ho oe D 9 www vwT25campergnfo a useful site for enthusiasts and owners of VW 25 T3 Vanagon campers MANUAL REFRIGERATOR DIAGNOSTIC FLOW CHART NO OPERATION Check Supply Voltage 1 110 Volt Plug 2 Wire Size pues as Necessary Correct as Necessary Replace if Defective Check Fuse NOT OK Correct as Necessary Check wiring Correct as Necessary Check Switch Page D 6 20 Para 66 Cprrect as Necessary C
17. E The formula for calculating amps amp OHMs Watts Volts 120 12 AMPS Volts 120 Amps OHMs www vwT25camper info a useful site for enthusiasts and oWRidfs of VW T25 T3 Vanagon campers 2 Dometic BULLETIN 45 MAY 1983 Replacement of cooling units 760 Cooling unit 531A will replace 530A in production and service When installing 531A as replacement for 530A three new holes should be drilled in the cooling flange New holes 1 3 16 29 mm down Furthermore the hole for the air channel no longer necessary in the burner box should be covered by a piece of aluminium tape No combustible material must be used Cover this hole www vwT25camper info a useful site for enthusiasts and owners of VW 25 Vanagon campers 9 Dometic REFRIGERATOR BULLETIN REVISED AUGUST 1984 38 CROSS REFERENCE OF REFRIGERATORS MANUFACTURED BY A B ELECTROLUX AND DOMETICARE PROCEDURE CHANGES SUBJECT Dometicare Procedure An out of warranty cooling unit purchased from Dometic for installation on an Instamatic Magic Chef Hadco or GE refrigerator does not qualify for our three year Dometicare cooling unit coverage We will warrant cooling units purchased from Dometic for installation on other than Dometic refrigerators for two 2 years providing the installation is within our established installation specifications We will offer our three year Dometicare coverage on the following cooling
18. K AMMONIA SOLUTION STRONGAMMONIA SOLUTION LIQUID AMMONIA AMMONIA VAPOR HYDROGEN GAS HYDROGEN amp VAPOR www vwT25camper infs 2 useful site for enthusiasts and owners of VW 25 T3 Vanagon campers aR esa ee CONDENSER i E Hipp E CIIM 2 EVAPORATOR b VAPOR PIPE SIPHON PUMP BOILER
19. OSTIC FLOW CHART NO GAS OPERATION Models Equipped with Automatic Reigniter A Check Gas Pressure OK Correct as Necessary NOT OK Page D 6 13 Para 37 B Correct as Necessary Check Gas Supply Page D 6 14 Para 40 Check 12 Volt D C Correct as Necessary Supply NOT OK P Check Switch D Correct as Necessary Page D 6 20 Para 66 OK E Check Thermostat Correct as Necessary NOT OK Check for Continuity OK F Clean Assembly amp Check Flue amp Burner Orifice as Necessary OK G Replace Electrode Check Electrode Page D 6 19 Para 62 www vwT25campgr info a useful site for enthusiasts and owners of VW 25 Vanagon campers NOTES www vwT25camper info a useful site for enthusiasts and owB rs of VW T25 T3 Vanagon campers OPERATION amp DIAGNOSIS OF DOMETIC MANUAL REFRIGERATORS WWW V pios amper info seful site for husiasts and o owe 7 This is Dometic s Manual Refrigeration Diagnosis and Troubleshooting program In this program we will discuss the way an absorption cooling unit operates and the diagnostic procedures used to troubleshoot the complete refrigerator system Before we begin extensive troubleshooting procedures on the cooling unit let s take a few minutes to see how it operates THE ABSORPTION SYSTEM WATER SEPARATOR CONDENSER EVAPOR
20. RCULATION LEAKER This type of fault means the unit has lost its charge it s known as a leaker To the touch this unit will be warm at the boiler and extremely hot at the absorber In this condition we are still boiling ammonia but have no hydrogen for evaporation www vwT25camper info a useful site for enthusiasts and owpgrs of VW 25 T3 Vanagon campers metic CHANGING THE Dometici March 1987 HINGE POSITION MODELS 2600 2602 2800 2802 3600 3601 3800 amp 3801 WHEN CHANGING THE HINGE POSITION If the door s open when the latch assembly is in the locked position adjust the hinge door Insure that the door latch assembly operates assembly Follow the outlined steps to complete properly after changing the hinge position from this procedure left to right or vice versa with the following checks l Open the door and remove the two 2 front decoration screws located underneath A The refrigerator door s opens and closes the upper hinge assemblies easily 2 Remove the front decoration by lifting B The door gasket seals smoothly and completely the decoration upward on all sides C Slide the latch left to the locked position and try to open the door s The latch assembly should keep the door s from opening NOTE A hard pull will release the door latch assembly and the door s will open This is not a fault 1f an adjustment is required repeat the above procedure to determine the eff
21. RIGERATOR FOR MINIMUM DIMENSION SEE INSTALLATION INSTRUCTIONS SSSA RS A SS CHECK FOR RESTRICTIONS IN AIR DUCTS OR VENTS See 5A C Some smaller models may be installed with two side wall vents instead of using a roof vent For this type of installation make sure the top of the upper vent is the correct distance above the refrigerator See FIG A3 The minimum dimension for this measurement is listed in the Installation Instructions Arrows indicate direction f h del of flow through sealed Combustion System Alternative positions for SIDE VIEW OF REFI 2 FOR upper ventilator Sd ii FIG A3 CHECK MINIMUM HEIGHT See Installation Instructions po Lower Arrows indicate direction Ventilator ww vwT25camper ihfer Cdoling Unit enthusiasts and ow Vanagon 9 1 1 Bulletin R61 7A continued 5 After two hours of operation check the temperature on the back of the cooling unit with your hand at the locations shown PERFORMANCE TEST First perform all the preliminary checks described previously Remove all food from the refrigerator and place all controls in the OFF position Place an accurate thermometer in an ice cube tray half filled with water and place the tray in the center of the lower food storage compartment NOTE If a remote reading thermometer is used allowing temperature readings without opening the do
22. afety valve it flows to the gas jet and burner These have been specifically designed to eliminate most of the normal main tenance required due to the corrosive contami nants in the gas as well as soot and rust which fall from the flue pipe The jet has an orifice made of an industrial ruby which has been laser beam drilled Each model of Dometic refrigerator uses a different size orifice in order to maintain the required amount of heat at the siphon pump To clean the jet and burner soak them in an alcohol base solvent and allow to air dry DO NOT use a pin or needle This will distort or shatter the orifice 48 If you determine that disassembly is required be aware there are two model designs for manual refrigerators The design pictured here will be discussed first 49 Shut off the main then disconnect at the back of the refrigerator Remove the cover over the thermostat and burner protection cover at the right 90 Now disconnect the m volts at the terminal block and unplug the 120 volt cord Remove the two mounting screws on the left and pull the metal locking arm out from under the burner housing Vanagon camper owners D 6 1 6 S 61 The control assembly will now drop down and can be pulled outward for service 52 Pictured here is the other model design Make sure the main gas supply has been shut off and disconnect the gas supply line at the refrigerator Remove 3 screw
23. atch assembly still will not engage the base can be repositioned to reorient the door as follows 1 Turn the refrigerator on its side to gain access to the four 4 base screws Loosen all four 4 screws slightly 2 Reposition the base so that the door catch retainer FIG 7 engages with the latch 3 Retighten the base screws while holding the base in its new position By following the above listed procedures you will be able to correct any door latching problems incurred when reversing the hinge position on your Dometic refrigerator If you have any questions concerning this procedure contact our Technical Services Department at DOMETIC SALES CORPORATION 4 509 South PoplaWsyw vwl 25camper info a useful site forBASE SCREWS LaGrange IN 46 amp fithusiasts and owners of VW 25 T3 Vanagon campersD 93 PROCEDURE FOR CHANGING COOLING UNIT Bulletin R55 7A April 1987 The following categories have been established predicated on similarity of design and procedure for replacement of cooling units Most Dometic refrigerators are covered in one 1 of these categories SPECIAL NOTE After the cooling unit has been installed the initial start up time can be shortened by tilting the refrigerator from side to side and then from front to back before the refrigerator is turned on TILT SIDE TO SIDE Run the refrigerator on a bench for 12 hours after the cooling unit has been installed all food shou
24. d out of level This special design can be identified by the round insulation box around the boiler rather than the square cornered box used on older units FIG B2 Older Style Current Style Boiler Enclosure Boiler Enclosure Blockage symptoms on the newer cooling units almost always indicate trapped liquid in the evaporator which can be corrected by proper leveling and allowing the cooling unit to cool off before restarting 6 If the temperatures are satisfactory in Step 5 continue operating the unit with power directly to the heating element for a total of 10 12 hours The doors must be kept closed for this entire period 7 If the temperature is within the previously mentioned guidelines the problem is not in the cooling unit See Section Il OTHER CAUSES for additional items that could be causing a loss of cooling 8 If the temperature in the food compartment is higher than the acceptable limit the cooling unit is probably defective If you are still in question as to the performance of the cooling unit please contact our Techni cal Service Department 219 463 4858 See the next paragraph before changing the cooling unit 9 The importance of adequate air flow across the cooling unit cannot be emphasized too much A minor restriction in the venting system will not create a problem on cooler days the available air flow will still provide adequate cooling due to the lower temperature However on a hot day
25. e refrigerator Thermal mastic is not used on these units Apply sealing permagum sealing tape on mounting plate FIG F3 yyww vwT25camper info a useful site for FIG F1 enthusiasts and owners of VW 25 Vanagon camperd 9 Bulletin R55 7A continued 4 Tighten screws securely to obtain proper seal 5 Install heating elements completely back into the pocket and plug in FIG Fl 6 Reconnect burner assembly to chimney FIG Fl NM capillary tube into proper position FIG F2 SEALING PERMANGUM Sealing FIG F3 THERMAL MASTIC IS NOT USED G Category 7 RM182 REMOVAL OF COOLING UNIT 1 Remove six 6 screws from burner cover FIG Gl 2 Disconnect burner from chimney 4 screws FIG Gl 3 Remove heaters from boiler case FIG G1 4 Carefully pull out thermostat capillary tube FIG G1 5 Remove two 2 evaporator screws and take out ice tray support FIG G2 6 Remove eight 8 screws holding unit from rear FIG G1 Remove two 2 screws holding gas line gasket FIG Gl INSTALL REPLACEMENT COOLING UNIT l Trim the Styrofoam portion of the cooling unit if it does not go freely into the refrigerator 2 Apply thermal mastic on the evaporator coil B FIG G3 3 Apply sealing permagum sealing tape A FIG G3 4 Reinstall thermostat capillary tube ww vwT25camper info Tighten screws securely to obtain proper seal Install the
26. e cooling coils are not normally damaged in this fashion and once proper leveling is main tained the cooling process will resume 2 Spirit or bubble are no longer being supplied with the new style refrigerators as the RV or vehicle only needs to be leveled so it is comfortable to live in with no noticeable sloping of the floor or walls For diagnosis the new style cooling units that incorporate the protection boiler system can be differentiated from the older style coils by the shape and design of the outer boiler box cover on the rear of the cooling unit These units will incorporate a circular metal cover 21 while the older style utilizes a square shaped enclosure We will discuss diagnosis and troubleshooting of these units in more detail later in the program www vwT25camper info a useful site for enthusiasts of VW T25 Vanagon campers 22 The coach vent system must be able to provide a way to direct the hot air produced by the action of the cooling unit out away from the installation of the refrigerator 23 In a good installation nad should be as little open space as possible surrounding the sides and top of the refrigerator to achieve proper air flow All potential dead air pockets should be blocked or baffled to insure that heat from the cooling unit won t be trapped in these spaces and reduce efficiency In addition the cooling unit should be at least one inch f
27. e met These are precise heat specified ven tilation and proper leveling ABSORBER _ ABSORBER VESSEL ELT EHT WU Guu GAS TEMPERATURE EXCHANGER ABSORBER VESSEL LIQUID TEMPERATURE EXCHANGER d WATER SEPARATOR CONDENSER EVAPORATOR PUMP crc xaT utres iussit ee e o RC BOILER M rorem THREE REQUIREMENTS FOR PROPER OPERATION 1 Level 2 Air Flow Ventilation 3 Heat www vwT25camper info a useful site for enthusiasts of VW T25 T3 Vanagon campers 10 We will now take a closer look at how the cooling unit functions in normal operation When proper heat is supplied to the boiler ammonia vapor is produced and rises in the siphon pump carrying with it a weak liquid ammonia solution As seen from this drawing the siphon pump or pump tube is an internal arrangement within the boiler section The boiler section utilizes the ammonia water liquid solu tion in the absorber and as it is heated turns the solution into a strong ammonia vapor which is needed to operate the system This strong ammonia vapor rises from the pump tube to the condenser coil Any deviation from the listed amount of heat to the absorption system will alter the ammonia to water ratio which in turn will decrease the cooling unit s overall efficiency The weak am
28. e tube assembly of the cooling unit The baffle causes the heat supplied by the gas burner to stay at the boiler assembly a longer period of time This allows the absorption system to work as efficiently on LP gas as other heat sources WATER COLUMN The pressure rating given to LP gas line pressure Usually this pressure can be varied by adjusting the regulator on the LP supply tank A manometer is the device used to test LP gas pressure www vwT25camper info a useful site for enthusiasts arld amp vners of VW 25 Vanagon campers To understand the absorption principle we have set up several refrigerators to inspect and diagnose Carefully touch the absorber and boiler sections of each unit and record your findings Proceed with TYPES OF BLOCKAGE caution as some of these units could be extremely HOT Listed below are three types of units you will be testing GOOD COOLING UNIT Carefully touch the unit at the boiler box and the absorber area These areas should be approximately the same temperature regardless of the ambient temperature The equal heat between the boiler and the absorber indicates the fluid circulation within the unit is good BLOCKAGE One of the faults with a cooling unit is blockage This can happen when the unit is operated off level or if too much heat has been applied to the boiler area To the touch this unit will be extremely hot at the boiler with little warmth at the absorber In other words NO CI
29. ectiveness of the repair SMOOTH FIT PROPER SEAL SMOOTH FIT 3 Loosen the screws that hold the upper PROPER SEAL hinge in place 4 Reorient the door so the catch retainer on the door will engage with the latch assembly Usually lowering the door will accomplish this MOVABLE 5 FIG 1 enthusiasts and owners of VW T25 Vanagon campers Bulletin R54 7A continued 5 Hold the door in its new position and carefully retighten the hinge screws being careful not to change the hinge position 6 Close the door and again determine if the latch is now operational 7 If more adjustment of the door position is necessary the center hinge screws may be loosened to reorient the door in the proper position 8 Again retighten the hinge screws to allow the latch to operate properly SPECIAL HINTS TO ADJUST DOOR l If there is a large distance between the lower door catch retainer and the latch adjusting the hinge position still may not allow the latch to operate properly LATCH FIG 5 LOWER CATCH EXCESSIVE RETAINER GAP 2 Remove the upper and if necessary the center hinge pin s This allows you to remove the refrigerator door s 3 Place a metal 1 4 flat washer available at any hardware store over the lower hinge pin and reinstall the door s This will raise the door to engage the latch assembly On very rare occasions two 2 washers may be required If the l
30. ed THREE REQUIREMENTS FOR PROPER OPERATION 1 Level 2 Air Flow Ventilation 3 Heat w vwT25camper info a useful site for enthusiasts and owners of VW 25 Vanagon campers Since the absorption system utilizes no mechanical pumps or compressors to circulate the refrigerant within the system proper leveling is required to provide correct refrigerant flow in the gravity feed system Without proper leveling refrigerant within the cooling coils will collect and stagnate at certain areas When this happens the cooling process will stop 17 On the older style soning units equipped with square boiler box covers this condition can cause permanent cooling unit failure As we can see from this drawing square boiler box cooling units utilize an exposed siphon pump tube which will become excessively super heated in an out of level condition This can allow the rust inhibiting agent to chemically break down and permanently block or restrict the normal refrigerant flow through the pump Shaking tipping or so called burping the refrigerator will not loosen or dislodge the blockage The only recommended service procedure is to replace the cooling unit To prevent this occurrence proper leveling is of utmost importance when the RV is parked for any length of time 18 To level these units 19 spirit or bubble level should be placed in the approximate front and center of the floor of the
31. ent heating elements are as follows RM360 135 watts RM460 150 watts RM660 190 watts RM760 275 watts These elements are identical and are covered under the same part numbers The difference being that the newer elements have been rated at 115 volt input rather than 110 volt input The American Gas Association now requires that every refrigerator be supplied with a spare parts list included inside the cabinet They are also requiring that all literature packaged inside the cabinet from this point on rate electrical input at 120 volt A C Therefore the new spare parts list supplied with the refrigerator will list the wattage at 120 volt input as follows 360 150 watts RM460 160 watts RM660 210 watts RM760 295 watts Once again these elements are identical to the previous elements and are covered under the same part numbers which are as follows RM360 173734 01 3 RM460 173736 0118 660 173738 0114 760 173740 0110 Should a customer be concerned that the wattage stamped on the heating element does not correspond to that shown in his spare parts list the above information should be passed on to him www vwT25camper info a useful site for enthusiasts and owners of VW 25 T3 Vanagon campers THE ABSORPTION SYSTEM WATER SEPARATOR RETURN PIPE lt WEAK F AMMONIA ABSORBER PIPE ABSORBER VESSEL HEATER POCKET WEA
32. gerator has cooled the lower compartment to the desired temperature C Air circulation within the food compart ment is important for proper cooling DO NOT place paper on the shelves or over fill the compartment with large cartons etc D Do not put hot food in the refrigerator Allow it to cool in room air first www vwT25camper info a useful site for enthusiasts and quyners of VW T25 Vanagon campers REFRIGERATOR TECHNICAL DATA Model No FC140 FC140 RA1302 00 RAK1302 15 RC65G RC65K RC150 RC150A RC150TEG RC 150TEG RC122 RC160E RC 160E RC160TEG 1 60 M52 e M70 RM18 RM23 24 RM36 RM36C RM36D RM36E RM36E RM45 46 47 RM45 46 47 RM46E RM46E RM60 66 RM60 66 RM66E RM66E RM66F RM66F RM67 RM67 RM67D RM67D RM67D RM75 76 77 76D RM100 RM100 RM182 RM182B RM182B RM190 RM211 RM215 2 REFRIGERATOR BULLETIN 28 Rev Feb 1989 Cooling Unit Orifice Size Heater Element Specs A c OHMs DC Part No amp Part No Watt Volts Part No Amps Resistance AMPS 32 2960082119 160 120 2960343123 ee 2 1 160 12 2960342117 13 3 Kerosene mn tm 2922000000 7 65 120 12 2922372020 54 222 54 2922302001 7 65 120 12 2922372020 54 222 54 2922471020 65 1202 2922372020
33. he thermostat is set to minimum or off If the sensing tube has lost its pressure even with the thermostat set on maximum you will have only low flame ORIFICE amp BURNER ASSEMBLY d DIAL SHAFT GAS OUTLET 7 DIAL SHAFT zr 3 GAS GAS INLET 4 OUTLET gt Wt 55 SCREW CLOSED VALVE www vwT25camper info a useful site for enthusiasts and owners of VW 25 T3 Vanagon campers 40 The most efficient are diagnose the gas system would be to first connect the gas manometer to the pressure test point With the thermostat set at maximum you must have 11 to 12 inches water column pressure for the refrigerator to operate properly If your manometer reads higher than 11 to 12 inches water column pressure the tank regulator is adjusted to high readjust it Make sure the gas system has at least 50 of the coach s LP appliances on at the time the system is being adjusted If the manometer reads 11 inches the problem of no cooling lies in the burner assembly flue pipe or venting 41 If you have less than 11 inches water column pressure the next step would be to remove the by pass screw NOTE The by pass screw reduces the pressure and volume of gas to the burner Shut off gas supply at the back of the refrigera tor Remove the by pass screw from the top of the thermostat 43 Use a by pass screw that does not have the small O ring at the botto
34. heck Thermostat Continuity Check www vwT25camper info a useful site for enthusiasts and owneggaaf VW T25 Vanagon campers MANUAL REFRIGERATOR DIAGNOSTIC FLOW CHART NO 120 VOLT AC OPERATION A 1 Check AC Power 2 Refrigerator Plugged in Correct as Necessary 3 Breaker NOT OK 4 Coach Plug OK Correct as Necessary Check Selector Switch Page D 6 20 Para 66 OK Correct as Necessary Continuity Check Check Thermostat Correct as Necessary Bulletin 28 Page 0 9 1 4 0 9 1 5 www vwT25camper info a useful site for enthusiasts and VW T25 Vanagon campers MANUAL REFRIGERATOR DIAGNOSTIC FLOW CHART NO GAS OPERATION Models Equipped with Piezo igniter Correct as Necessary NOT OK Page D 6 14 Para 40 Correct as Necessary Page D 6 20 Para 66 Check Gas Supply Check Switch Check Thermostat Correct as Necessary Continuity Check Correct as Necessary Check Gas Pressure Page D 6 13 Para 37 Correct as Necessary NOT OK No Obstructions Check Flue amp Burner OK Correct as Necessary Check Piezo Resistance Page 0 6 1 8 Para 58 Replace Electrod Page D 6 18 58 Check Piezo Electrode OK Check Spark Gap Correct as Necessary of Electrode to Burner NOT OK Page D 6 19 Para 62 www vwT25camper info a useful site fc enthusiasts and owR r amp of VW T25 Vanagon campers MANUAL REFRIGERATOR DIAGN
35. iasts and owners of VW 25 T3 Vanagon 4 0 Bulletin 617 continued Also make sure the distance from D Check the open space above the refrigera the bottom of the refrigerator to the tor If this space is 1 1 2 inches or roof vent is at least the minimum more it must be blocked off to prevent dimension given in the Installation hot air from being trapped above the Instructions for each model See FIG refrigerator See FIG A2 A2 If venting is suspected as a problem run the performance test described below with the refrig FIG A2 erator installed then run the same test with MIN 5 the refrigerator removed If there is a definite amd improvement in performance a venting problem is indicated Also see Section B PERFORMANCE TEST Item 9 SPECIAL VENTING FOR DIRECT VENT MODELS RM182 215 2192 These models are designed to be installed in small vans and are usually placed in a cabinet that is not open to the outside of the vehicle This means that air from within the vehicle MAXIMUM OPEN must be used to cool the condenser SPACE 1 1 2 IN See 5D Customers with this type of installation must be made aware that the vehicle interior must be kept from getting too hot If the vehicle is left parked in the sun with all doors and windows closed the inside temperature can quickly exceed 100 degrees and the cooling process will slow m di down or stop completely REAR VIEW OF REF
36. igniter senses the resis tance through the flame between the electrode and burner When there is no flame at the burner the resistance is high and the igniter begins sparking to light the burner As soon as the flame is lit the resistance between the electrode and burner drops and the igniter stops sparking The resistance is monitored by the igniter and if for any reason the flame goes out the igniter begins sparking until the burner is lit This insures that the flame will always be lit when desired Each time the igniter reigniter system sparks a light will illuminate on the lower left front corner of the refrigerator 60 If the electrode does not spark first make sure the igniter is receiving 12 volts If the igniter is receiving 12 volts and produces no spark it must be checked for operation 61 Turn the refrigerator ee remove the wire between the electrode and igniter Now turn the refrigerator to the gas mode If no internal clicking sound is heard the igniter is defective It is important to remove the high voltage wire that goes to the electrode from the igniter when you are checking the igniter for operation The high voltage wire and the electrode can be shorted to ground causing the igniter reigniter to think that the flame is lit resulting in no spark on gas operation 62 The distance oss tip of the electrode and the burner known as the spark gap should be 3 16 of an inch A greater distance will create a
37. ld be removed for testing FIG A2 FC140 Cooling Unit cannot be replaced A Category 7 RM46 RM46 1 RM663 RM2500 RM360 RM660 RM2300 RM3500 RM460 RM661 RM2400 REMOVAL OF COOLING UNIT 1 Remove heater s from boiler case FIG AI 2 Disconnect burner from chimney FIG A2 3 Remove evaporator screws inside refrigerator and remove cooling flange FIG A3 4 Remove screws holding clamp for capillary tube Pull capillary gently out of plug FIG A3 5 Remove screws holding unit from rear FIG Al FIG A3 P leverage os Rown and useful sie for enthusiasts and owners of VW 25 Vanagon camper 94 Bulletin R55 7A continued INSTALL REPLACEMENT COOLING UNIT 1 Trim the Styrofoam portion of the cooling unit if it does not go freely into the refrigerator Apply sealing permagum sealing tape on mounting plate A FIG A4 Apply thermal mastic on the evaporator coil B FIG A4 4 Tighten screws securely to obtain proper contact between the evaporator coil and evaporator flange otherwise improper cabinet performance may result 5 Install the heating element completely back into the pocket and plug in 6 Reconnect burner assembly to chimney 7 Reinstall capillary tube into proper position FIG A3 B CE A THERMAL SEALING MASTIC PERMAGUM TUA Sealing Tape B Category 2 RM100 RM763 RM1303 RM760 RM1300 RM2600 RM360
38. lectric mode the cut off valve is automatically closed When this same switch is turned to the LP gas mode the electric circuit is also automatically interrupted EVAPORATION A process that causes a liquid to turn into a vapor Whenever evaporation takes place heat is removed EVAPORATOR Section of the cooling unit where the cooling effect is produced Liquid ammonia evaporating in a hydrogen atmosphere takes place in the evaporator HEATING ELEMENTS Elements that operate off either AC or DC voltage that create heat to the cooling unit IGNITER REIGNITER igniter reigniter used on certain Dometic model refrigerators operates on 12 volt current On gas operation the igniter senses the resistance through the flame between the electrode and burner When there is no flame at the burner the resistance is high and the igniter begins sparking to light the burner As soon as the flame is lit the resistance between the electrode and burner drops and the igniter stops sparking The resistance is monitored by the igniter and if for any reason the flame goes out the igniter begins sparking until the burner is lit This insures that the flame will always be lit when desired Each time the igniter reigniter system sparks a light will illuminate on the lower left front corner of the refrigerator GAS PRESSURE For the refrigerator to operate properly on LP gas the gas pressure should be set at 11 water column pressure NOTE use the
39. m Reinstall this by pass screw into the thermostat www vwT25camper info a useful site for enthusiasts and owmerasof VW 25 Vanagon campers 44 Turn on the main gas supply and take a reading If the manometer now reads 11 inches the thermostat is defective and must be replaced 45 If the by pass screw e shows no change in gas pressure the problem lies with the gas supply to the refrigerator Shut off the gas supply remove the by pass screw replace it with one that has an O ring and turn on gas supply Remember to check for a gas leak At this time we will take a look at the rest of the gas system 46 The safety valve or ime failure safety device consists of a brass alloy valve housing and cap an electro magnet and a thermocouple which generates 14 to 30 millivolts when heat is applied to the tip It is used to energize the electro magnet in the safety valve The purpose of this device is to insure that the flow of gas is shut off in the event flame is lost at the burner If this should occur the thermocouple cools the magnet loses it magnetic field and the valve closes Most failures of this device are related to the magnet not the thermocouple Should this happen the complete safety valve should be replaced er ta www vwT25camper info a useful site for enthusiasts and ofibrs of VW 25 Vanagon campers 47 Once the gas has pum allowed to pass through the s
40. monia solution which remains behind is diverted to the top of the absorber coils to perform a function that we will discuss in further detail later in the program 11 The air that passes the condenser fins from the venting system removes heat from the ammonia vapor causing it to condense into a strong liquid ammonia solution As a liquid it then flows to the low temperature evaporator or freezer companment where it comes into contact with a hydrogen atmosphere When this occurs the ammonia begins to evaporate which draws heat from inside the freezer section to the rear of the cooling unit 12 This heat is then out through the upper vent which allows the refrigerators interior temperature to properly maintain food storage requirements Not all of the liquid ammonia evaporates in the freezer What is left continues to evaporate as it flows to the high temperature evaporator or food storage com partment WATER SEPARATOR SRR Ane annem CONCENSER 4 PUMP ILER 4 i i i 1 i 1 t 1 A l M d P www vwT25camper info a useful site for enthusiasts and owragrs of VW 25 Vanagon campers U3 As this process the ammonia and hydrogen vapors become intermixed and flow downward into the absorber vessel As the ammonia vapor comes in close
41. or the tray of water is not required Make sure the AC heating element is the correct wattage for the model being tested and that the resistance reading is correct See Checking Resistance of a Heating Element below Connect 120 volt AC power directly to the heating element leads make sure the FIG CONDENSER A E EA BOILER TEMPERATURE ENCLOSURE TEST AREA leads are not connected to the refrigerator circuit then check the voltage at the element with a volt meter Reading must show at least 115 volts CHECKING RESISTANCE OF A HEATING ELEMENT A simple test to check a heating element is to measure the resistance through the element with an ohmmeter The correct resistance in ohms can be calculated if the wattage and voltage ratings are known These ratings are stamped on all Dometic heating elements Use this Formula Volts Watts Volts Ohms Example Heating element rated 135 Watts at 110 Volts 110 13 5 110 or 110 1 23 89 4 ohms The ohm reading should be within 10 of this figure or between 80 46 and 98 34 ohms Use the lowest setting on the ohmmeter which will give an accurate reading When testing a 12 volt heating element a very accurate ohmmeter must be used because of the very low readings that will be found For example a 200 watt element will have a reading of 72 ohms less than 1 ohm TEMPERATURE TEST AREA Under normal operation the tempera
42. refrigerator is level Sometimes the vehicle is level but the refrigerator is not due to improper installation Place a level on the bottom of the freezer compart ment and check side to side and front to back levels see FIG Al Use a mirror if necessary to read the level 4 Carefully check door gaskets for proper seal A leaking gasket can allow enough warm air inside the refrigerator to overcome most of the cooling being produced REFRIGERATOR BULLETIN R61 7A DEC 1987 For a simple method to check gaskets close the door on a dollar bill then pull the dollar bill out If no resistance is felt the gasket is not sealing properly This should be done on all four sides of the door CHECK LEVEL BOTH WAY CHECK DOOR GASKETS FIG Al 5 Check the venting system to insure that ample air flow is provided at the back of the refrigerator A Check for and remove any restrictions in the vents such as filters installed by the customer bird nests in the roof vent or smashed louvers in the wall vents see FIG A2 B Make sure the correct roof vent has been installed Larger models such as RM100 760 761 1300 1303 2600 2800 2802 3600 3800 3802 and 4801 require a 5 X 24 opening for the roof vent Smaller models will also use the 572 24 roof opening To check this measure the actual opening in the roof DO NOT measure the roof vent itself See www vwT25camper info a useful EIG 2 enthus
43. rom the nearest surface made of combustible materials Please follow the installation manual for proper dimensions and clearances RVIA requires that the refrigerator be installed in such a manner as to provide complete separation of the combustion system and the interior atmosphere of the recreational vehicle This regulation requires all seams and joints in the enclosure be sealed The under counter installation is different The addition of a metal chute the width of the enclosure that extends from the upper side vent will help eliminate the possibility of dead air pockets It helps direct the hot air out the exhaust vent The best method for venting the absorption refrigerator is with a lower side vent and a roof vent Using proper Dometic vents will give you sufficient intake and exhaust areas for ventila tion 24 Heat application to do section of the cooling unit must be within the designed BTU s Never oversize the heating element on AC or DC power source Always use the proper size orifice for gas modes As explained earlier any deviation will cause a potential cooling unit failure THREE REQUIREMENTS FOR PROPER OPERATION 1 Level 2 Air Flow Ventilation 1 FROM COMBUSTIBLE MATERIALS j PATH OF 7 AIR FLOW 0 CLEARANCE FROM SIDE OF 1 FROM COMBUSTIBLE MATERIALS PATH _ AIR FLOW THREE REQUIREMENTS FOR PROPER OPERATION 1
44. s on the burner cover plate The sheet metal assembly should now slide out from the back of the refrigerator 54 Remove the 2 screws from the plastic cover Also the 2 screws on the left and 2 screws on the right of the metal bracket www vwT25 enthusiasts and ownerg of VW T25 campers camper info a useful site for Vanagor 55 There are 3 screws in the burner area that must also be removed Please note these are machine screws not sheet metal type It is important for them to be reinstalled in this area only 56 The control assernbly will now drop down and can be pulled ouward for service 57 On the present line of manual refrigerators we use one of two methods of igniting the burner flame Shown on the right is the piezo system on the left is the igniter reigniter 58 The piezo lighter is assembly which generalty does not need maintenance When the button is pushed a spring loaded striker creates a spark If there is no resistance when pressing the button the piezo igniter is defective and must be replaced If the piezo snaps or has resistance when the button is pushed but there is no spark the problem lies in the electrode or electrode wire www vwT25camper info a useful site for enthusiasts and owners of VW T25 T3 Vanagon campers 59 The igniter reigniter used on certain Dometic model refrigerators operates on 12 volt current On gas operation the
45. tat GAS amp ELECTRIC TER THERMOSTAT SAFETY VALVE through the safety valve thermocouple PRESSURE TEST HOUSING 85 est housing Ba ti ry Qe www vwT25camper info a useful site for enthusiasts and owlegss of VW 25 Vanagon campers 36 and onto the oad h burner assembly Remember that except for the connection piece all fittings are O ring sealed Whenever the system is separated the O rings must be replaced 37 To diagnose the d connect a manometer to the test point With the thermostat on maximum you must have 11 inches water column pressure at this point If you have 11 inches pressure your problem Is to the right of the test point If you do not have 11 inches water column pressure the problem Is to the left Lets take a closer look A the gas thermostat In this drawing we will review how a thermostat functions When the thermostat is working properly the manometer will read line pressure when set at maximum and the refrigerator is trying to cool From this drawing you can see the gas flow when the refrigerator is trying to cool The gas flows through the thermostat at line pressure without restriction The valve is open at this time The valve is now closed and the gas must flow through the by pass screw the gas is now diverted through the by pass screw which regulates the size of the low flame This condition can only exist when the refrigerator is cold or t
46. tend into retainer tube approximately 36 FIG Bl d RM3600 amp RM3800 have internal thermostat with capillary tube clamped to cooling flange FIG B4 7 Reconnect the burner assembly to chimney SEALING PERMAGUM Sealing Tape A THERMAL MASTIC B FIG B5 C Category 3 RC160 RC150 REMOVAL OF COOLING UNIT l 2 Remove screw disconnect burner from chimney FIG Cl Disconnect heater wires from terminal block FIG Cl a Remove heaters from boiler case FIG Cl www vwT25camper info a useful site for Remove screws holding unit from rear FIG Cl Disconnect green grounding wire FIG Cl Pull out on cooling flange to remove fr evaporator coil FIG Cl Pull thermostat capillary tube out gently and move so that cooling unit will clear FIG Cl Remove cooling unit by hinging out on right side FIG Cl INSTALL REPLACEMENT COOLING UNIT 1 SEALING PERMAGUM FIG C2 Trim the Styrofoam portion of the cooling unit if it does not go freely into the refrigerator Apply sealing permagum sealing tape on window insulation A FIG C2 Apply thermal mastic on the evaporator coil B FIG C2 Tighten screws securely to obtain proper seal otherwise improper cabinet performance may result Install the heat elements completely back into the pocket and attach to terminal block FIG Cl Reconnect burner assembly to chimney FIG Cl Reinstall capillar
47. test port at the rear of the refrigerator to take this reading www vwT25camper info a useful site for enthusiasts of VW T25 Vanagon campers Glossary of Terms continued 13 15 17 18 ORIFICE JET A small brass fitting that is mounted on the gas line just prior to the burner This device incorporates a very small opening to greatly reduce gas flow to the burner The orifice is cleaned by using an alcohol based solvent and allowing to air dry PIEZO LIGHTER Self contained lighter assembly that is used to generate a spark to light the refrigerator on LP gas This unit contains a quantity of quartz crystals that when pushed or snapped produce a spark There are no serviceable parts on this device SAFETY DEVICE An assembly of parts safety valve magnet and thermocouple that shuts off the supply of LP gas to the burner assembly if the flame goes out for any reason This is to ensure that a concentration of unburned gas does not accumulate in the refrigerator vent area SELECTOR SWITCH This is also a circuit interrupter on the 12 volt DC 120 volt AC and gas sides of operation on the refrigerator When the customer selects either DC AC or GAS operation the selector switch directs electricity first to the thermostat and on to the heating element or igniter reigniter When this switch is turned off the AC or DC circuit is interrupted SPIRAL BAFFLE Spiral metal device that is hung in the flu
48. thusiasts VW 25 T3 Vanagon campers 28 One of the faults ee a cooling unit is a blockage This can happen when the unit is operated off ievel or if too much heat has been applied to the boiler area To the touch this unit will be extremely hot at the boiler with little warmth at the absorber In other words no circulation 29 This type of fault UE a lost charge It is known as a leaker To the touch this unit will be warm at the boiler and extremely hot at the absorber In this condition we are still boiling ammonia but have no hydrogen for evaporation 30 The following of the program examines the Dometic manual refriger ators gas and electrical systems Dometic refrigerators are designed for both piezo and automatic ignition Both HCT 1 1 1 i 1 1 WARM CIRCULATION OF BOILER V HOT GAS ONLY systems will be covered this presero5camper info a useful site for tation enthusiasts and owners of VW 25 Vanagon campers 31 Let s look at the Aron Dial refrigerators UNDERSTANDING and see how the gas flows THE GAS SYSTEM SHUT OFF VALVE 32 Gas flows from the gas line to the shut off valve and to the connection piece GAS LINE CONNECTION PIECE COMBINATION into the combination gas nd electric thermos
49. ture at the absorber coils A and the boiler B should be approximately the same If the temperature at the absorber coils A is much hotter it indicates loss of refrigerant and the cooling unit must be replaced If the temperature at the boiler B is very hot and the absorber coils A are cool it indicates that the refrigerant is not circulating properly This could indicate A Liquid trapped in the evaporator sections caused by out of level operation for a period of time Resetting the refrigerator to a level position will not necessarily correct the problem as liquid can remain trapped even after level is corrected Shut off the heat source and let the system cool down then re start it and observe the temperatures at A and B again after several hours If the same condition exists it could indicate B A permanent blockage within the boiler pump tube caused by too much heat applied to the burner oversized orifice or heating element or prolonged operation of the unit when out of level or with restricted ventilation This type of blockage consists of hard deposits inside the boiler pump tube This condition is not repairable and the cooling unit must be replaced www vwT25camper info a useful site for enthusiasts and owp amp 20f VW 25 Vanagon campers Bulletin R61 7A continued NOTE The cooling units currently being used are specially designed to prevent overheating of the boiler tube even when operate
50. y tube into proper position FIG Cl Sealing Tape A enthusiasts and own amp PSof VW T25 Vanagon campers Bulletin R55 7A continued D Category 4 RM190 RM2190 RM2 192 REMOVAL OF COOLING UNIT 1 Remove cover and flue tube then disconnect burner from chimney FIG D1 2 Remove heater s from boiler case FIG DD 3 Remove screws and take out evaporator fins and shelf FIG D2 4 Release holding clamp for thermostat capillary tube and pull tube out gently FIG D2 5 Remove one 1 screw and bend two 2 tabs and then pull cooling unit out FIG DI INSTALL REPLACEMENT COOLING UNIT l Trim the Styrofoam portion of the cooling unit if it does not go freely into the refrigerator 2 Apply thermal mastic on the evaporator coil B FIG D3 3 Apply sealing permagum sealing tape on window insulation A FIG D3 4 Tighten screws securely to obtain proper seal 5 Install the heating elements completely back into the pocket 6 Reinstall capillary tube into proper position 7 Reconnect burner assembly to chimney and replace cover A SEALING PERMAGUM Sealing Tape B THERMAL MASTIC E Category 5 RM211 REMOVAL OF COOLING UNIT 1 Remove cover and disconnect burner from chimney FIG El 2 Remove heater from boiler case FIG 3 Remove three 3 screws holding unit from rear FIG E 1 4 Pull cooling unit part way out and then disconnect
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