Install & troubleshoot tips for gas powered refrigerators

ALWAYS have a professional plumber install your unit and test for gas leaks
ALWAYS plumb inlet gas line with a sediment trap, drop tee for collecting debris
ALWAYS leave the house and then call 911 if you smell a gas or ammonia leak
ALWAYS yearly clean burner assembly and flue above of any carbon buildup
ALWAYS install high altitude orifice when working above ~8000 foot elevation
ALWAYS shut-off the gas supply to a vacant house and turn off all appliances
NEVER operate with both gas power and electrical back-up at the same time
NEVER install gas appliances atop carpeting or near flammable wall coverings
NEVER store items atop a gas fridge since paper can fall behind and catch fire

Always have a licensed professional plumber install your gas appliance with dual-stage adjustable regulator, 1/2 inch brass fittings with shut-off valve at wall and reinforced flex line to sediment trap drop-tee before appliance. Same plumbing details common to gas hot water heaters. Installation can shake sediment loose in pipes. Best to trap in drop-tee before reaching relatively small burner and clogging jet. Particularly important at higher elevations to maintain constant flame at burner. Test for leaks by spraying every connection with dish soap and water mixture, looking for bubbles (leaks).

Functionally, in terms of unit operation, you can transport on the side if you must. When not possible to transport standing up, we suggest laying unit on the side opposite hinges to relieve stress on the door. Remove all interior door shelves and loose parts to avoid damage. It is especially important to allow unit to sit idle upright for at least 24, if not 48 hours before firing up after transporting on the side. Be extra careful not to damage the cooling coils on the rear of unit. If you see yellow fluid leaking that smells like ammonia, you just pierced the cooling coils - leave the house and then call 911. 

Always allow a gas refrigerator to sit upright and idle for at least 24 hours after moving. Transporting a gas refrigerator shakes the ammonia mixture in the cooling tubes, causing bubbles to appear. After moving into place, be sure to let it sit for at least a day to settle out the bubbles. Vapor lock can occur, if not allowed to settle out, causing the refrigerator to fail to reach lower temperatures. Typically, "burping" by turning on one side for several hours and then upright before immediately firing. 

A little smoke from the burner is common when first lighting gas appliances. There is always a little machining oil left on the burner parts and the flue above from the manufacturing process, so don't be surprised if it burns off with a little smoke when first lit, especially when you do not clean them first. Your installer normally wipes excess oil off burner as part of the installation process after checking burner for gas leaks (as per page 3 of installation manual), but they sometimes do not clean thoroughly. The flue above rarely has excess oil on it, but it could use a good cleaning too, if you wish to avoid a little smoke at first. 

Recommend installing a shut-off valve within reach of installed unit since gas supply must be shut off completely, at the source, when moving a gas appliance. Be sure to have your installer use a long enough, quality stainless steel braided gas flex line to allow refrigerator to be pulled away from the wall for cleaning underneath and behind at burner and flue assembly. Connection at unit is 3/8 inch SAE male flare connection. Do not hide the shut-off valve behind refrigerator.

Always equip the gas supply tank with a professionally installed, two stage (dual) adjustable regulator. Normally set at standard 11 inch water column pressure, but can vary for best flame. Too low or too high of gas pressure can cause small burner appliances to flame oddly. Single stage regulators, as seen on BBQ grills, are not dependable. Your home's propane tank should already be equipped with a two stage regulator, per local plumbing code, but if you have multiple large gas appliances on the same line, and have issues with flame quality, consider installing a dedicated two stage regulator for just the refrigerator. Worst case scenario: when a huge 60,000 Btu furnace kicks on, it can cause a small 1500 Btu burner to flicker and possibly blow out if there is a cross-breeze. If you are having problems at high altitude, it may help to upgrade to an adjustable regulator so pressure can be dialed-in for optimal clean blue flame, not a dirty yellow burn.

Install an automatic changeover valve (regulator) when running gas appliances off small propane tanks. When one propane tank runs dry, the changeover valve automatically switches over to the second tank to maintain constant gas pressure in lines. This prevents the gas refrigerator from turning off and having to be relighted after tank is changed. Changeover valves are commonly packaged with two stage regulators as a single device and generally marketed for the RVs.

Always level your gas refrigerator (front to back and side to side). In the boiler of the cooling unit, ammonia vapor is distilled from ammonia-water mixture and carried to the finned condenser where it liquifies. The liquid flows to the evaporator inside the refrigerator where it creates cold by evaporating into the circulating hydrogen gas. If the evaporator is not level, liquid may accumulate forming pockets which may impair the gas circulation or block it completely, in which case cooling will stop.

The feet/legs are designed for leveling, not for pushing the fridge back and forth, especially when loaded. Gas refrigerators are heavy for their size, so moving only when empty (and gas supply disconnected) is always suggested. To lessen chance of damage to leveling feet, thread them all the way back up into body/frame when moving a gas fridge. We highly suggest permanently installing a set of Teflon coated "furniture sliders" under the refrigerator's feet. Teflon furniture sliders are available at most hardware and Big-Box retailers. These 'friction-less' plastic pads snap right onto the feet, allowing them to slide very easily and not catch on the floor. 

Always allow at least minimum clearances for proper operation and safety. We suggest 6 inches top and 2 inches on sides and back, but the minimum Servel installation manual states: 4 inches top and 1 inch on all sides. The 4 to 6 inch top clearance is critical to proper operation with more ventilation providing better cooling performance. Keep the unit out of direct sunlight to reduce energy needs. Never install any gas burning appliance on a carpeted floor or near flammable objects or walls. Ideally, the wall behind and sides of any cabinets are fire-proof materials and/or covered with non-flammable metal.

Never install a gas refrigerator designed for residential use in a moving vehicle. The Servel RGE400 units are not designed for mobile home, boat or recreational vehicle use. An open flame is simply too dangerous in a moving vehicle. When a gas refrigerator is in motion, continuous rolling and pitching may not affect cooling operation, but not being level will. Operation on back-up electrical power is the only option when in motion and even then is not assured.

Never run the electrical power and gas power thermostats at the same time. Backup electrical power 110 volt AC operation is STANDARD equipment on the Servel gas fridge. Should you ever run out of gas, it's very handy. Just be certain to never run both heaters at the same time. Serious damage will result to the thermostat and possibly the cooling unit.

Never try to cool an empty gas fridge as it confounds the thermostat. You should always have something in the freezer and refrigerator compartments for the thermostat to sense temperature. If you run the unit with an empty freezer (or refrigerator compartment) thermostat will cycle on more often, using much more fuel. Your gas fridge will reach temperature quicker and maintain it more effectively when you first load the freezer and refrigerator with frozen milk jugs full of water.

ANY gas freezer compartment is not designed for quick freezing large quantities of food. All foods should be pre-frozen before being placed into the freezer compartment. If you need to put unfrozen food into the freezer, add no more than it will freeze within 24 hours. Rule-of-thumb is 2 pounds per cubic foot of freezer space adding up to 5 pounds per 4 hours until freezer is full. Keep refrigerator as full as possible, while leaving air space between packages, to help with cooling. Defrost freezer should you notice ice build-up on the cooling plates. Avoid chipping at ice. Allow it to defrost naturally with door open.

Replacing an older gas refrigerator? Crating and padding is recommended immediately after removal. If you intend to use the defunct appliance for furniture, take extreme steps to protect those rear coils. Cooling liquid is very pure ammonia... wrapped inside what is likely a pure LEAD 'radiator' pipe on units pre-1970's. Should you puncture the cooling system, yellow colorant should alert you and odor is hard to miss. Ammonia in contact with bleach creates fumes that are "even more" toxic, so always store bleach in another room. Some plumbing companies specialize in extracting 'industrial' ammonia coolant (and freon, etc), but we cannot offer personal referral. When you approach contractors on the phone, state you want to have them "remove ammonia cooling liquid from a refrigerant system". Best not to lead-off with 'household refrigerator'. Such firms are often equipped with on-site vans for industrial locations, but you might benefit from bringing the fridge to them.

troubleshooting tips for any brand of gas refrigerator

Should your gas refrigerator not be cooling properly or having trouble staying lit, and you are not located above 8000 foot elevation where a high altitude orifice is required, the first thing for your licensed service technician to check is proper setbacks for air circulation and level the unit. The next step is to clean the burner and ensure that sediment and moisture have not invaded the gas lines. Metal and particulates can flake off older or improperly installed supply lines, clogging the burner jet. One would notice an erratic or 'dirty' yellow flame with the only answer being to replace the gas line from regulator to shut-off valve at wall feeding the unit. It might be possible to have a professional flush the lines, but likely best to just replace.

Next replace the regulator with a quality dual-stage adjustable set at about 11 inch water column pressure. This is very important to ensure efficient operation since too low or too high of gas pressure can cause small burner appliances to flame oddly. Single stage regulators, as seen on BBQ grills, are not dependable. Your home's propane tank should already be equipped with a two stage regulator, per local plumbing code, but if you have multiple large gas appliances on the same line, and have issues with flame quality, consider installing a dedicated two stage regulator for just the refrigerator. Worst case scenario: when a huge 60,000 Btu furnace kicks on, it can cause a small 1500 Btu burner to flicker and possibly blow out if there is a cross-breeze. If you are having problems at high altitude, it may help to upgrade to an adjustable regulator so pressure can be dialed-in for optimal clean blue flame, not a dirty yellow burn.

Next step should the burner still not stay lit, and you are not at high altitude above 8000 feet, chances are the thermocouple has corroded (clean the tip) and/or perhaps not properly seated. Last resort is to replace the thermocouple, part number #2931496042 shown on parts list. Unfortunately, Dometic Corporation no longer provides parts and service since they stopped distributing Servel in 2018, and we have yet to find another source for replacement parts in the United States.

Should you be experiencing inadequate cooling the thermostat may not be functioning properly. Perhaps the probe has corroded (clean the tip) and/or perhaps not properly seated. Or maybe the freezer just needs defrosted to expose the cooling plate in freezer compartment. Do not chip at the frost, only shut off unit and open the door to freezer and collect water as it melts. Replacing a thermostat part #2007199041 is time consuming and should be performed by a skilled technician. 

If an older gas refrigerator is not cooling at all and everything else is solid with parts and installation, there is a chance enough coolant has seeped out of the closed loop system over the years to create a bubble void above the burner and require 'burping' of the unit. When a large enough bubble settles over top of burner, coolant will fail to circulate. Should burner be left on when coolant is not circulating, it will overheat the pipe and can lead to failure of cooling pipe and leakage of coolant. You rarely see vapor lock with units that are constantly operating, but can occur when refrigerator is turned off and on repeatedly for short time periods, as seen in a vacation cabin. Unit is 'burped' by turning on side opposite the hinges for several hours and then right side up. 'Trick' is to set upright and fire immediately to get the bubble circulating. There should be no need to 'stand on its head' burping, but that is a last resort repair option to explore.

Cooling coils used to be solid lead and seepage of ammonia cooling fluid was unknown. When they were forced to switch to steel tubing, molecular seepage was inevitable, but it normally takes more than 20 years to see any noticeable effect with a quality unit. If your relatively new unit has more leakage than normal, it may have occurred when left unattended. One should never leave any gas appliance burning when you are not in residence for extended period. Fire danger aside, should it vapor lock and you are not around to shut it off, the pipe above burner will overheat and allow excess seepage. 

We cannot recommend any propane powered LP gas freezers or larger-bodied refrigerators. We'd be selling one if any of them were dependable. Those we have seen over the years are commonly powered with the same closed-loop cooling system used for the Servel RGE400 refrigerator freezer. Functionally, there is a limit to the amount of cooling possible with gas. Larger refrigerator bodies and freezers tend to not pass the 'ice cream test' freezing at or below -5 degrees where ice cream stays hard. Gas freezers are lucky to maintain below 10 or 15 degrees and run hard to accomplish even that, causing premature failure. One can keep already frozen food stable with a large-body propane refrigerator, but they will not maintain at the below zero temperature required to freeze raw food/meat properly or make ice cubes at a reasonable rate. Ideally, fish or meat two inches thick should freeze completely in about 2 hours. Rapid freezing prevents undesirable large disruptive ice crystals from forming. Thawing damages the cells and dissolves emulsions, causing meat to "drip" and lose juiciness.

Best practice for off-grid clients is to use a dedicated generator to power an efficient, conventional electric chest freezer. Ice maker units are available for after-market installation. Key is to keep the gaskets moist, install a tight latch, and heavily insulate the chest freezer with four inches of blueboard, leaving plenty of air flow underneath and behind for cooling. Best to install a remote 'outdoor' thermometer inside the chest freezer with alarm to alert you when to power-up the generator. With sensors and some after-market engineering, one can automatically power-up a small dedicated generator, at a certain temperature, for a certain amount of time. At the very least, you can manually shut-off generator during the afternoon and overnight. Surprising how long a well-insulated chest freezer can maintain below freezing temperatures.