Q: Are old heaters safe, what should look for, what repairs should I expect to make?
A: A brand new heater can be just as, if not more dangerous than an older heater if it is not hooked up or vented properly. That is one reason to stay with the original installation if at all possible. An existing heater, even a 50 year old one, is safe if the care and use is exercised that even a new appliance deserves. A heater uses LP gas and produces Carbon Monoxide (CO) – two elements that must be treated with respect. A heater should be inspected carefully and all repairs made before using it, and then inspected annually. The burner can (combustion chamber) and flue are most critical, and should be cleaned of debris and insure any holes or rust-through holes are either welded or a new burner can fabricated – both of which a good welding shop can accomplish. The connection to the exhaust vent line should be air-tight and the line unobstructed. Burning LP gas produces water vapor, which will rust the steel and iron burners and combustion chambers. Most were designed to rust effectively without altering performance or safety. A good sandblasting now and then will help clogged burner rings and make it easier to inspect the chamber. The burner pilot light operates much like the hot water heater does- see below for more maintenance tips.
These older units used no electricity, something only the catalytics nowadays can boast. The older furnaces can also warm up a cold trailer quickly, something a catalytic can’t do – catalytic heaters are good for maintaining temperatures once achieved – especially at night. And let’s face it, the older furnaces look cool compared to the hidden noisy under-counter boxes that pass for RV heaters today.
You do have more replacement options with the newer forced air heaters, as they are usually a generic Suburban and Atwood unit that can be hidden in cabinetry.
As with any combustion device, always verify annually that the combustion chamber and exhaust flues are 100% sealed tight, and always leave a window slightly open for ventilation when using the heater.
Q: My local RV dealer won’t work on my heater in our 1950’s trailer. What’s up with that?
A: To find someone other than yourself to repair an older heater will be rather difficult. Big issue is the liability coverage, and no parts support from manufacturers because of that.
Most heater units, if taken care of, are no more dangerous than when they were new 30-40-50 years ago, but we as a society are. Back then people still accepted a personal responsibility for their own safety, and took it upon themselves to check the operation and condition annually, knew to sleep with a window and vent open, and were just more mechanically inclined than the general public is nowadays.
Your best bet will be the smaller Mom & Pop dealers as the owner or a long-time skilled employee will usually be doing the work. Keep trying until you find such a dealer that will work on it.
Q: Our Suburban forced air furnace no longer will light and run. What are some of the usual causes?
A: It’s usually one of three scenarios, all easy to fix. First, insects and debris can get into the burner air inlet. Since there is insufficient airflow, the electronic igniter won’t start. Secondly is a bad sail switch (“air-prover”). This micro-switch activates by the airflow from the combustion blower and is set to reach a certain RPM before allowing the gas and ignition to activate. A third problem is that if you are not on shore power, the battery may be run down and won’t turn the blower fast enough to initiate the sail switch. This can also apply to the earlier pilot light models. The sail switch closes to open the main gas valve when the blower causes it to close the circuit confirming that fresh air is incoming for combustion and exhaust air is being blown out.
Here is a source for Suburban parts & schematics: http://www.marksrv.com/suburbanparts.htm
Q: I’m not sure if the heater in the trailer we just got works. How should we go about checking it out?
A: It is best to first remove the heater from the trailer and work on it on the bench, using a propane tank and a barbecue regulator and hose to op-check. They come with a standard 5/8″ flared female fitting that will mate up to most RV LPG appliances. Use a 12v car battery for the models that require power to run fans & igniters. While there give it a thorough cleaning and inspection. Look for rusted burner cans & flues, leaking or damaged lines. Make sure the pilot nozzle is not plugged. Repair any of these before proceeding. Look for black LPG goo in the intake, lines or mixing chamber of the gas control. Check the pilot filter too. If residue is found in any, then disassembly and a cleaning of the gas control is in order. Carb cleaner or other rubber safe cleaner works the best. Be very careful of any gaskets and little parts. On older units if you you lose or damage them, you’re out’a luck.
Q: Our heater pilot doesn’t stay lit. What is the cause?
A: When you push down on the pilot button, you are allowing gas to go directly to the pilot burner. The flame in turn warms up the thermocouple next to it, which in turn opens up a valve in the gas control, allowing gas to go to the main burner if the gas control knob and thermostat setting call for it. If the flame won’t stay lit, it is most likely a pilot adjustment problem or a thermocouple problem.
The pilot needs the right amount of gas and air to burn a bright blue with just a tinge of yellow at the tip of the flame. Adjust the little set screw (usually under a plug in the gas control body). You should already have checked for LPG goo and leaking lines above. Another cause can be wind or draft blowing it out. Make sure you are testing with all the little shrouds in place.
If the flame is OK, then examine the thermocouple. If it is a hydraulic or pneumatic type (connected by a small copper tube), check for loose fittings in the little line. If it is electrical, check the connections, and then replace the thermocouple if they look OK. All online and local RV stores and small appliance places have them.
Q: The heater pilot works, but the main burner won’t light. Any ideas?
A: If it is a newer Suburban heater, check earlier item above first. For heaters in general, a no-light burner means that something is not allowing the main valve to open. Vintage Gas Control Valves are very simple and durable devices, and rarely fail. It almost always come down to some simple external reason or periphery unit causing the problem. It could also be something as simple as a low, but not fully empty, LPG tank.
Q: The main burner flame won’t shut off after the trailer warms up. (or)
The main burner turns off too soon.
A: Both of these problems are usually related to the Thermostat. They can be of three types on vintage trailers. The oldest is the pneumatic bulb type. As the air from the room is drawn into the heater, it passes over a copper bulb. As the air in it warms up, it works by increasing air pressure against a diaphragm in the control body, closing the supply of gas to the burner. These types of gas control valves will have temperature settings on the knob on the valve. The other two types are remote mounted thermostats, usually on the wall. They can be of the micro-volt variety, which produce their own electricity to actuate the solenoid, or a more conventional type that uses trailer power.
For older thermocouples, it is the same same the pilot – check for leaking or plugged lines. Some self-contained models will use a thermocouple with wires attached. On these, clean the contacts and measure with an ohmmeter. You should get a resistance value greater than 0, but less than a dead short. Replacement is the only cure for bad units.
For wall mounted thermostats, without anything connected to the terminals on the gas control valve, the burner will just burn forever. A little solenoid in the control body is activated by the external thermostat. That is a good way to isolate if you have a thermostat problem for a no-light of turns-off-too-soon problem. If you have a Robertshaw milli-volt control, the external thermostat will just have two wires coming out of it, and they attach to the gas control valve terminals. If you have a more conventional system, much like a house thermostat, then there will 2 additional wires supplying low-voltage to the thermostat. You are on your own figuring out which you have – make sure before proceeding to any other troubleshooting other than simply replacing the thermostat with a like kind, or isolating it down to the thermostat with the wide open test mentioned above. You can wreck a milli-volt solenoid by applying voltage to the terminals.
Q: The gas control valve is a rusty pile on my Panel-Ray heater, where can i get a new onE?
A: Actually this applies to most early RV Heaters and Hot Water Heaters. The RV manufactures used gas control valves of the era that were used on household hot water heaters: General Controls, Robertshaw-Grayson & Unitrol. Old HW heaters are good sources of parts, and there are also modern generic non-electric replacement valves available. You might have success by taking a valve and probe into a small appliance parts dealer and find a substitute. Forget any idea of asking for a control for a certain brand name of heater, or for a “1964 Airstream”.
Q: The burner flame in my heater is distorted and not burning well. The Pilot appears OK. What might be the cause?
A: The burner nozzles (jet) on these LPG heaters are usually a tiny hole, and some heaters with their vertical jets, like our Hydro-Flame, are very susceptible to plugging up with scale and rust. A quick clean-up of the jet will restore the flame. Also, for some reason, mud-daubers just love building nests in heater vents! After 7 years, we’ve learned to seal ours off now when not camping.
Hot Water Heaters
Q: Are repair parts available for the older Bowen Hot Water Heaters??
A: Bowen was bought by Atwood many years ago, and some of the newer parts can be adapted to work, such as regulators, pilots lights and burner tubes. For example the pilot light assy is part number MPD 91603. Contact Atwood for more information.
Q: My hot water heater tank has rusted through. The new 6 gal heaters available come with an ugly white flimsy door. How do you replace the HW heater?
A: This is a quite common replacement. The new Atwoods and Suburbans are smaller than the old Bowens (old Atwood). Remove the old unit from the outside, it is attached around the lip of the opening and sometimes with a couple of brackets into the wood floor. Fashion an adapter plate to fill the gap at the top and sides and to provide attachment for the old exterior shroud if required. Secure this plate to the opening using the old screw locations along with the new HW heater. A little sealant prior to assembly will make a weathertight installation. This method will allow you to keep the old exterior cover with the new unit.
If you have the vintage Bowen heater that has the external shroud for the hot air exhaust on just one half of the opening, the newer Suburban models exhaust the hot air on the same side, making reusing the existing shroud even easier. Otherwise, fabricate a deflector shield from sheetmetal and pop-rivets to deflect the exhaust upwards and out the top.
Here’s a website showing the replacement of a Bowen heater with a new 6 gal Atwood. The same idea would also work for keeping the original shroud – don’t use the cheapy one that comes with the new unit. http://www.ldservice.com/tim/airstream/wacky_water_heater.htm
Q: A prior owner threw away the original outside cover when they replaced the Bowen Hot Water Heater and installed a flat panel that looks out of place. Can I get a replacement cover?
A: The only two sources exist for these. One would be a wrecked trailer, but they always go first. It is also possible to have a sheet metal shop make a similar shroud using a picture of one as a guide using novelty embossed aluminum and perforated aluminum sheet. If you have a pan brake and shear, you can do it, too. Only thing missing would be the nameplate and the original style latch – which may be a blessing on the later. More info available here in this Restoration Topic section.
Q: I’m worried about hard water sediment plugging up our HW heater. Any ideas?
A: Atwood, the current manufacturer of the post 1968 Bowen style water heater recommends an annual blowout of the water heater. Their method involves attaching an air fitting to the city water inlet, applying clean 40-50 PSI air and blowing the water of the heater. They say the scavenging action of the air bubbles will clear the calcium buildup.
If you already have a build-up of material, you can use a gallon or two of white vinegar to loosen the calcium deposits. Put it in, let it soak overnight, flush it out good. You may have to repeat, depending on how much is in there.
Q: What Air-Conditioners did Airstream offer as standard options?
A: The Armstrong “Bay Breeze” was used when they first became available in 1960, and then as long as they were made. Sounded more like a hurricane than a breeze, but if you compare components and operation with newer RV AC’s the difference was significant. These units are definitely worth repairing. The Armstrong’s used commercial grade parts. Airstream then had to change to a Coleman Delta TX that had inside/outside air and did a decent job. When that model was discontinued, Airstream changed to the Dometic Penguin. Airstream has used the Penguin on all their trailers ever since.
Q: When were Airstreams first pre-wired for Air-Conditioning at the center vent opening?
A: According to Airstream records they did not start pre-wiring for air-conditioning until 1962-1964 (depending on model/factory). You can tell if there is a spare 20amp breaker in the electrical control box. In the few years prior that AC was available, wiring was run from the fuse panel on custom AC installations only.
Q: What about the water condensate air-conditioners produce. Where does it go?
A: The air-conditioner needs to be installed in a contoured pan, specific to the brand of air-conditioner – available from Airstream dealers only. This pan is connected to a drain hose that goes down between the inner and outer skin and exits the floor and belly pan. This drain was preinstalled on 1967 and later models, and has to be retrofitted on older trailers. This pan also adapts the AC to the rounded top of the Airstream.
Q: Are the roofs equipped to support the weight of an air-conditioner?
A: Not all until 1969. Prior to that, some models will have frame members adjacent to the vent opening, but others require two fore & aft stringers be placed between frames (“main bows”), in between the skins.
Q: How do RV refrigerators work?
A: Simply put, they heat up liquid ammonia, changing it to a vapor that as it expands absorbs heat. As the vapor condenses back into a liquid, it releases the heat it absorbed in the tubing inside your refrigerator to the outside of the refer on the back via the cooling tubes. This heat is exhausted out your trailer via natural convection, and is the reason your trailer has a lower and upper vent for the refer (some early trailers had the lower intake air only come from the interior cabinets). The heat to initiate the cycle comes from a 110v heater coil or a small LP gas burner flame.
Q: The refrigerator in my used Airstream doesn’t work. The dealer says it is shot and I need a new one – cost: $900. Is there any way to shortcut this? Can it be fixed?
A: Older refrigerators are sturdily built using long-life materials. The newer materials are not as sturdy, such as plastic vs. metal and electronic circuit boards and controls that will have a limited life. Plus, they are made with so much newer looking plastic that they are very noticeable. Most shops will want to replace you refer because it takes less skill to replace with new than to repair old, plus the chance of quick success is greater. There are RV appliance shops that will work on the older units, so check around.
Another option is fixing them yourself. It first takes an understanding of how they work (see above), and then troubleshoot and restore the unit, cleaning, disassembling and adjusting per the manual if available. The most common failure of refrigerators is accumulation of dirt and rust on the coils inhibiting heat transfer, or the gas burner becoming plugged with rust from the coils or by spiders, or the thermocouple tubing/fittings leaking or out of position. The enclosed tube system for the ammonia gas/liquid is rarely the problem as they almost never leak or plug unless damaged or mis-operated. On pre 1970’s refers, once the tube is compromised, professional repair is almost the only option unless you find another donor unit to swap and combine parts with.
Q: My refrigerator is missing, so I have no choice other than replace. Other than the cost of $800-$1200, what problems will I have?
A: The biggest concern is that new refrigerators are of different sizes than the older units, and cabinets may require substantial modification. By moving more controls to the front, replacing the steel box with plastic and foam, and replacing the aluminum frame with plastic, the sizes are close, but not quite the same. Another thing to watch out for is that many of the older refrigerators had cutouts in the back that are not duplicated on modern units.
Q: My gas refrigerator works only on gas but not on electricity. How come?
A: The cooling circuit of your refrigerator depends on a small section which must be kept hot in order to heat up the ammonia in the tubing. It can be heated either by a gas burner, or an electric resistance heater. The two circuits are usually independent. The electric heat usually has a heating element and its own thermostatic control. Make sure the heater element is inserted to its full length in its pocket or receptacle. If the electric heater is only partly inserted, the heat distribution will be incorrect. Another possible failure is the heater element has burned out. You can determine which by using a volt-ohm meter. Modern heating elements can be adapted to fit in place of inoperative units. If it is a modern refer, the most likely failure is the controller Circuit Board. Replacement boards are available from RV Dealers.
Q: My gas refrigerator works on electric power only, not gas. How come?
A: The cooling circuit of your refrigerator depends on a small section which must be kept hot in order to heat up the ammonia in the tubing. It can be heated by a gas flame or by an electric resistance heater if so equipped. Usually these two systems are completely separate. It sounds as though service is needed for the gas burner portion. The usual causes are the burner orifice being plugged or damaged, or the gas control being plugged or needing adjustment. Plugged burner tips can be cleaned out with solvent and compressed air, and replacement burner tips are available from small appliance parts distributors. Make sure the thermocouple flame sensor is in the flame path per the manual, and that all the fittings are tight. The thermocouple compresses the air in the tubing as it is heated, opening a valve in the gas control it connects to. If there is any air leakage, the valve will not open. Make sure the flame height and color is adjusted per the manual, and that the vents are free and clear of blockage. Also, make sure that there is LPG pressure at the control valve. The VAC Archives have started collecting and posting older fridge manuals in their Online Library.
Q: I’ve heard you can restore a poor working refrigerator by “burping it”. Is this true?
A: It is to the extent that if the problem was caused by running the refer while off level or without adequate cooling air, resulting in overheating. This will cause an excessive vaporizing of the ammonia within the boiler. After some hours of this, the liquid mixture in the boiler is very weak and the circulation of liquid stops. The refrigerator should be removed after allowing sufficient time to cool down. Turn the unit upside down several times so that the liquid in the absorber vessel can be mixed with the liquid in the boiler. This will restore the liquid balance.
Q: What are replacement cooling packs?
A: Starting in the ’70’s refers were made with a modular cooling system that can be replaced external to the refer box. Check out some of the suppliers in this section.
Q: The door gasket on my refrigerator is falling apart. What can I do?
A: The best place to get replacement fridge gaskets is an appliance or appliance parts store. Take in a section of gasket and find one close. They have the kind that is captured by screw-on flanges, the push-on kind, and the adhesive kind. It won’t be a one piece molded part, as it is sold by the foot, or in some cases will be the size of a home refrigerator, but you cut the four lengths you need out of it. Angle-cut the corners with a 45 deg notch, leaving the outside surface intact. Seal the corner up with matching colored silicone sealant.
Q: I’m installing a gas refrigerator in place of an old missing one. Any concerns?
A: The biggest would be ventilation. Early Airstreams didn’t provide adequate ventilation for the cooling tubes. When it comes to refer venting, the key is “draft”. The taller & tighter your chimney, the better the draw of cool air over the coils of the refer. The ideal is a screened intake in the floor (what Airstream started using in the ’60’s), into a relatively tight compartment made using the refer back, side cabinets & outer wall of the trailer, continuing upward and exhausting out the top of the trailer.
The top roof vents used in the 1950’s looked more like smokestacks, and are still available at better home centers, hardware stores, and plumbing/heating supply houses. They have both the 4″ round capped ones, usually used on the heater vents, and the long oval one, usually used on the refer’s. Both have storm collars, made of aluminum and look much like the ones from the ’50s, only now made in Mexico.
Q: My old Marvel Fridge is 110v only. How can I keep the vintage look, yet the advantages of a modern gas refrigerator?
A:One way professional restoration shops do it is to keep the door and accessories of the old unit, and then modify and mount it on the body of a new similarly sized Norcold or Dometic refer in place of the new units’ door. Use a new door gasket (see above). This will work obviously if you have the skills, tools and know-how (ingenuity?) to do it.
Q: the stove on the trailer we just got is grease encrusted, rusty and the oven doesn’t work. I’d replace it, but it the style is just so cool. Is there anything i can do?
A: The older ranges, Dixie’s and PreWays for example, are really household apartment ranges of the era. Even the newer Princess, Coleman and Magic Chef stoves, ovens and ranges use the same technology as their household cousins. Restoring & using old appliances is hot right now, and the fallout to appliances will be a good result. There are companies that will restore household vintage ranges, a search on the Internet under “vintage appliances” brings back about a dozen. Find one local (avoid shipping), and they will even do your RV range.
Most stoves don’t need full restorations, just a good going through. Stoves are easiest gas appliance to work on, ovens a little more difficult. Remove the unit and work on it on the workbench. Hook up a propane tank and a barbecue regulator and hose to it. They come with a standard 5/8″ flared female fitting that will mate up to most RV LPG appliances. While there give it a thorough cleaning and inspection. They disassemble easily, but take good pictures and label parts and hardware. Rusted parts can be stripped, sandblasted and repainted or chromed. Check in the phone book under metal stripping, metal plating, and powder-coating.
Replacement grates and clips are available from RV dealers. The same with the burner control valves. Some of the vintage stove companies have replacement knobs that may fit, but would require a full set to look right.
Ovens are a little more complicated. Most use safety interlocks. Basically this a always on pilot that heats up a thermocouple, that allows gas to flow to an intermediate safety flame when you turn the oven on. This intermediate valve also is controlled by the oven temp sensing thermostat. Only when the intermediate flame heats up its thermocouple, does the safety valve allow gas to flow to the main burner. It’s quite an operation to watch. These complicated devices actually are pretty reliable, usually only succumbing to errant 0wner disassembly or plugging up from the LPG supply. The pilots are all adjustable, but are usually only worth messing with if you don’t know what the PO did to the appliance. Otherwise, it’s just a matter of trial and error to determine where the gas flow stops, and why. Replacement parts from newer RV ranges can be adapted to work in older units. Here’s a view and adjustment instructions for the typical Harper Oven Control used on most Magic Chefs and Princess stoves.
When working on old appliances, remember to leak check all connections, check for leaks and allow unburnt fuel to always dissipate before lighting.