VW Vanagon Westfalia / Dometic Fridge Maintenance
By Frank Condelli
The Dometic fridge that’s installed in your VW Vanagon Westfalia camper needs some maintenance now and then to keep it working well. This article will address this issue.
Some symptoms that indicate the need for this maintenance are no or hard starting on the propane setting, improper cooling, ventilating fan noisy or inoperative, and the LED run indicator not working. To execute the needed maintenance requires that the fridge be removed from its location in the camper cabinet.
Step 1. Begin by making sure the propane valve is shut on the propane tank. You can test to make sure it is by trying to light the stove after you have shut the valve off. If the stove does not light then the valve is shut properly.
Step 2. Remove the fridge flue vent on the side of the van by removing the three screws holding the outer most vent ring. Then remove the five other screws you will find underneath this ring. Remove the all the pieces including the gasket. If there is any rusting around the opening in the wall of the van now is a good time to look after this situation. Keep track of the order in which the parts come off, as it is very important they go back in the same order. All these parts must be cleaned of any corrosion before re-installing them. The rubber parts should be coated with Krown rust proofing oil or a similar product. Use the Krown on the metal side of the van, all the metal plates and screws unless replacing the screws with stainless steel ones, which is a good upgrade. If the metal plate that goes onto the rubber gasket has the two holes that hold it to the side of the van enlarged to the pint the screws do not hold you can use soft metal washers behind the screws.
Step 3. Go to the front of the fridge and remove the door by sliding it upwards on the hinges, remove the front panel of the cabinet by removing the plastic screw caps by prying them off with a sharp object like a penknife blade and remove the screws. Remove the small screw in the metal part of the cabinet at the upper left hand corner of the panel. The panel can now be slide to the right to disengage it from it slot in the cabinet and pulled forward. Now there are four more screws on the sides. Two can be located by opening the door of the storage compartment below the sink and looking on the wall next to the fridge you will find two small holes in the wood paneling and recessed in these holes you will find the two screws. Then on the other side in the storage compartment next to the fridge beneath the swing out table you will find one more and then in the lower compartment next to the fridge you will find the last one. Remove the metal vent on the side of the cabinet so that you can access the exhaust tubes and help them not get hung up as they come through the wall of the van and the interior panelling.
Step 4. Disconnect the propane line. Removing the drawer under the sink and reaching in behind the fridge to access this fitting can accomplish this.
Step 5. Disconnect the 110-volt plug from the fridge from its receptacle in the cabinet underneath the sink. Disconnect the two 12 volt electrical connectors, one with three wires and one with one black wire. All these wires should be held to the back of the cabinet by a strap that has a snap connector. To undo the snap, you man need to pry it open with a small screwdriver.
Step 6. Remove the fridge by sliding it out toward the middle of the van, slowly. You should now be able to slide the fridge all the way out. The exhaust pipe will most likely get hung up as it tries to clear the opening in the wall of the van so watch that it clears this point. You will have to tip the fridge at an angle to allow the exhaust pipe to duck under the cabinetwork and let the fridge come all the way out.
Step 7. Once the fridge is free standing in the middle of your van take it to a workbench to complete the following maintenance. The fridge must be blocked to level for all these operations to be done correctly.
Step 8. Turn the fridge upside down and block so that it is level. Let stand in that position for a minimum of 24 hours. This will dissolve any of the crystals that “MAY” have formed in the chemicals that are inside the cooling system. Some of the work described below can be done with fridge in this position. For others, you will have to wait until you can turn the fridge right side up.
Step 9. Around the backside of the fridge you will see the ventilating fan, cooling fins and propane burner and more than likely you will find this area full of dirt, cobwebs, and all kinds of goodies that have accumulated there over the years. Clean this area and the top of the fridge using a vacuum and or compressed air.
Step 10. Open up the combustion chamber of the burner by removing the six screws that hold the bottom of the burner in place. Before removing these screws undo the fitting to the propane line and remove the screw holding the sparking starter and remove the starter. Now remove the six screws and remove the bottom cover and see how much dirt has accumulated in there. Clean this out and also check to see if the air intake going to the front of the fridge, with the small screw cap, is not blocked. If it is blocked which is highly likely, take a length of wire and slide it down the tube until air can pass then blow it out with compressed air. Check the propane lines are clear. Remove the jet and place it in a small jar with Lacquer thinner so that it is submerged for 15 ~ 30 minutes, then blow it out with compressed air. You can use a small copper wire to pass through it to aid in cleaning it. Do not force the wire, as you do not want to damage or enlarge the jet. You should be able to see light through the jet when holding it up to a strong light source. Before re-installing the jet, blow air through the propane line by using compressed air from a compressor source, input with a blow gun at the main line connection at the top rear right hand corner of the fridge. Open the main propane valve, set the thermostat to MAX, push in and hold the bypass/safety valve, then blow for a few minutes to make sure the lines and valves are clear. Now you can re-install the jet and burner pipe once your satisfied the lines, jet and burner pipe are clear and clean.
Step 11. Check the exhaust and air intake stack tubes. They need to be free and clear of any and all obstructions. Use compressed air here again. Check the exhaust pipe for cracks especially in the corrugated flex section. If it is cracked you will need to repair or replace it. Small cracks can be repaired successfully with muffler cement and or muffler tape.
Step 12. Check the gasket between the bottom cover and burner pot and if it is bad you can make a new one from a piece of inner tube or similar material or you can use Loctite, Ultra Copper High Temperature RTV Silicone sealant on the old gasket.
Step 13. After your confident that everything is nice and clean, check that the spark starter is working by pressing on the starting button on the front of the fridge. You should see a nice healthy blue spark. If the spark starter is not working then you will need to find out why. The wire may be broken or the spark is no longer any good in either case it will need to be replaced.
Step 14. Once your confident the combustion chamber, exhaust pipe and air intake pipes are clean and the starter is functioning you can replace the cover of the combustion chamber, the spark starter and the propane line.
Step 15. Now you want to test the burner. This can be done by taking the propane tank and the feed line to the burner from your backyard barbecue and connecting to the propane connector on the back of your fridge. Open the tank valve and start the fridge as per the instructions on the fridge door. If all goes well the fridge should start up relatively easily. You can check to see what the flame looks like by removing the Piezo starter from the firebox and peering into that hole. The flame should be blue and even over the whole run of the burner pipe. Turn the thermostat up and down and the flame should vary, if not the thermostat valve may be faulty. Now let it run for awhile so that your sure it’s working well. You can shut it down and restart it a few time to insure that it fires right up consistently, if not the Piezo may not be in the proper location and you should try to reposition it. You can check the operation of the cooling system now if you wish by taking the door of the fridge and placing it on the fridge and block it somehow to seal as best you can. After an hour or so of operation the temperature of the cooling pipe behind the cooling fins inside the fridge can be checked with an infrared thermometer or just place an ordinary thermometer on the lower ice cube tray. The temperature on the rivet to the far left is the coldest, it should reach -7 Celsius.
Step 16. While the fridge is running you need to verify that the black wire leading away from the small start valve which is located at the end of the push-in starter valve on the front of the fridge is providing 25 ~ 35 millivolts. That wire is connected to a Thermocouple at the end of that valve. See the explanation of how this works here > Thermocouple. This Thermocouple is what turns on the LED on the control panel telling you that the fridge is running.
Step 17. Turn the fridge off, wait awhile then re-start the fridge again. It should start right up.
Step 18. Now that your fridge is working perfectly on propane. You should also check the electric ventilating fan. Connect a source of 12-volt power to the Brown and Blue wires at the fridges 12-volt power plug, the Blue is the negative and the Brown is the positive. Using a heat source such as hair dryer or heat gun heat the thermocouple, the small disc device attached to the cooling fins and wired in series to the fan, just until the fan starts up. The fan should come on and go off as the thermocouple cools. If the fan does not come on then either the thermocouple or the fan is defective. Bypass the thermocouple to check. Replace the defective parts. A good suitable replacement for the fan is a 2″ computer muffin fan.
Step 19. Check the cooling fins inside the fridge. The cooling fins/ice cube tray holder assembly is clipped to the cooling tube behind it and uses Thermal Mastic on the mating surfaces to provide proper transfer from the cooling pipe to the fin assembly. If this unit is loose then the cooling system will not function properly and the Thermal Mastic will have to be renewed. Remove the cooling fin assembly by pulling it forward. Clean the mating surfaces and coat the inner surface on the cooing fin unit with Thermal Mastic and reinstall the unit by pushing it back onto the cooling tube and set it level. Once the Thermal Mastic has dried the cooling fin assembly will stay in place.
Step 20. Check the 110-volt operation plug in the 110-volt plug into a working 110 volt household outlet and turn the appropriate switches on the front of the fridge. It will take awhile for it to get cool; the only way you can tell it’s working, so be patient. You can do the same thing for the 12volt operation by supplying 12 volt power to the 12 volt electrical connector, Black is the positive and Blue is the negative, then turn the appropriate switch on the fridge. The two heating elements are retained in metal tubes welded to the exhaust stack. They are retained in these tubes by setscrews at the bottom of the tubes. They need to be tight for the heat transfer to work properly so check them. You can slide the metal cover over the insulation of the exhaust stack up wards to access these setscrews. Now once you’re satisfied the fridge is working well your ready to re-install it.
Step 21. Check the air pump. The air pump, operated by the control knob on the far left of the control panel, is there to introduce fresh air into the firebox. Since the firebox and its intake and exhaust tracks are completely sealed, a way of getting fresh air, oxygen more precisely, to allow the propane to light, is needed. Remove the end of the plastic hose from the pump where it connects to the metal tube and put it into a vessel containing water. Actuate the pump and you should see bubbles. No bubbles, the pump is not working and will have to be repaired or replaced. There was a modification service bulletin issued to perform on the air pump to make it work better. Check to see if this modification has been done. If not you should do it now. Remove the pump, remove the original plastic air supply line and check valve and disassemble the pump. Drill out the exit port where the plastic tube connects with a #40, 3.5mm, 9/64″ drill bit. Disassemble the pump piston assembly. Install an O-ring between the metal plate on the side of the circlip and the piston. This O-ring needs to fit tightly on the rod. You should be able to find a suitable O-ring at your local auto parts or building supply. Discard the original plastic air supply line and check valve. Obtain a new check valve, Volkswagen P/N 055 131 101 or equivalent, drill out the two ports with the same drill bit used above, install this new check valve using two lengths of 4mm, (5/32″) ID x 65mm (2.5″) long surgical tubing or equivalent. Be sure the one-way valve is installed in the proper direction, air to fire box when pump is actuated. Secure the check valve to the ignitor with a tie wrap.
Step 22. Before you re-install the fridge you should take the opportunity to clean up the space in the van behind the fridge. Upon close examination you may find rust and debris there that needs to be cleaned up. The Fiberglas insulating material that was used to insulate the walls of the Westfalia tends to soak up and hold any humidity that collects in there and I found that removing this insulation and replacing it with 2″closed cell Styrofoam that will not absorb moisture will be to your vans benefit. If your van is a Canadian model with the electrical outlet below the water tank and city water outlets then you will need to remove that electrical outlet and push the electrical cord into the storage compartment before trying to remove the Fiberglas. If it’s an American model then there is no need for this operation. Once the Fiberglas has been removed use a shop vac to clean all the debris from behind the cabinets. If the floor is still intact with no rust holes, remove the two rubber plugs from the drain holes in the floor so that any moisture that gets in there can drain out. Once all is clean spray the floor area between the cabinet and van wall, the wall and the wall support brace with a good rust preventive like KROWN or RUST CHECK. This will help stop any rusting already in progress and prevent further rusting. Now cut three 15″ x 16″ rectangles of the Styrofoam , insert them through the opening behind where the fridge was pushing them as far to the sides as you can then cut another 15″ x whatever is missing and jam it in-between the pieces already installed to make up a complete wall covering. Tape the visible joints with house wrap tape. Now go to where you removed the electrical box and cut a hole in the Styrofoam so that the electrical box can be fitted trying to keep the Styrofoam as close to the electrical box tube as you can. You will need to make space for the hose clamp screw to fit also. Once the electrical box is back in place and the area cleaned up you can go about putting the fridge back in place. See pictures of this area by clicking > here. One last thing should be checked before re-installing the fridge. The City Water outlet connection where the brass fitting is screwed into the plastic housing tends to crack and leak. Whenever you turn on your sink water using the water from the water tank this city water line is pressurize right up to this fitting as there is a check valve in the plastic housing to keep the water from going out through the City Water inlet. This is a major source of water behind the cabinet that helps to cause the rusting away of that panel behind the cabinets. If this connection is leaking then it needs to be repaired.
Step 23. Replace the fridge by reversing all the steps you did in removing it making sure the electrical connectors are plugged together properly and the propane fitting is secure and then your ready to test it in the van. Turn on the switch on the electrical LED panel on the front of the sink~stove~fridge cabinet so that when the fridge lights on propane the green LED at the left bottom of the panel will light telling you the propane has lit. It may take a few minutes to light up on propane as the propane will need to make its way up the line from the tank to the fridge burner. Let it run for 15 ~ 30 minutes, shut it down and restart. Go for a drive with the propane service running, making sure the drain at the bottom of the fridge is closed, to see if the fridge stays lit while driving, it should with no problem. If it goes out then there is a leak in the intake~exhaust track to the burner pot and you will need to find it. Check the 110 volt and 12 volt services. If all went well then your fridge is once again ready for camping and cold beer.
If your sure the fridge is running, a simple method is to touch the exhaust plate on the side of the van, it should be hot so be careful, and the LED is not working you need to check the single black wire, the same one we checked before, to the control panel and if your sure that is correct then you need to check the board on which the LED is located. It could be the board; LED, resistor or the LM324 control chip is bad. The control chip is at the far right side of the board, Radio Shack part #276-1711; this chip controls the LED on the control panel board. The LED, resistor and chip can be replaced by obtaining them from Radio Shack or other electronics supply shops, then un-soldering and removing the defective piece and soldering in the new one.
The drain at the bottom LEFT HAND corner of the fridge can also be used to clean out the burner pot periodically between major servicing by using air from an air compressor through a blowgun. The higher the air pressure the better. You can also use this drain to get air into the firebox to make it easier to light the propane if it is being difficult to light, which sometimes is because of a lack of oxygen in the firebox. This is why Dometic installed the air pump on the front of the fridge control panel. That air pump I find is not sufficient and blowing air in there through a small plastic hose using air from your mouth will in most circumstances get the fridge to start up on propane. Keep this small plastic hose in the van as a tool to get your fridge lit.
There are two good upgrades that you can do while you have your fridge is out for service. One is to add a small, 2″, 12 volt, computer muffin fan inside the fridge to circulate the air which will provide more uniform temperature circulation when the fridge is full. The fan can be attached to the top of the cooling fins with tie wraps so that it blows air downwards. The wires from that fan can be brought to the rear of the fridge through the same hole as the thermostat’s capillary tube. The fan wires can then be connected to the 12 volt constant power to the LED panel through a small switch you can mount on the sink~stove~fridge cabinet front next to the LED panel. The second upgrade is to install a 3″, 12 volt, computer muffin fan in the City Water service port, which most of us do not use. The City Water service port is located appropriately directly in front of the fins that must dispel their heat. If you do not want to loose your City Water service then you can make a new hole in the side of the van next to the City Water service port to mount the fan. This fan can then draw out the heat from behind the fridge to the outside and will allow the fridge to operate properly on hot days. The heat from behind the fridge was designed to rise up into the van through the grillwork behind the top of the sink~stove~fridge cabinet and then out the skylight. Once the interior of the van reached 80 degrees F, the fridge will cease to transfer heat and will stop to cool properly. To proceed with this project, remove the City Water service port, cut off the rear of it so you have a housing with a flat surface to mount the muffin fan. Choose a muffin fan that will have at least two of its mounting holes line up with two opposing mounting screw hole of the City Water service port. Using spring clip type screw clips on the muffing fan will allow you to screw longer screws through the outlet, through the body of the van and into the spring clip attached to the fan thereby holding the whole unit in place. Run the wires from the fan up to where the LED panel is on the sink~stove~fridge cabinet and wire in to the 12 volt constant power found there through a switch you can mount next to the LED panel. If you want to be really creative find a small micro switch than can be mounted on the City Water service box so that the fan operates when the flap door is open. The flap door can be propped open with a Popsicle stick cut to the appropriate length and stored behind the flap against the fan when the flap is closed. I have done this but it does take some dexterity to accomplish.