TOPIC: Propane Fridge & Water Heater
INSTRUCTOR: Al Cohoe
Fridge and furnace problems usually not air or fuel problem -- but ignition problem.
Refrigerators ... Absorbtion types can work on propane, AC or DC...though DC marginal at best. Used to be simple, but with automatic features they've become troublesome. Needs to be level, or coolant won't circulate back. Last five years they are more tolerant. Nine times out of ten, problem happens when people run the fridge the night before to cool down for a trip, and they're parked at home on a very uneven surface.
To make something cold, you must remove the heat to achieve a resulting lower temperature. Heat is applied to boiler ... by either a propane or electric source .... Ammonia mixes with water. Want to boil off ammonia, but leave the water. So heat must be "correct". Ammonia is vaporized, some water is vaporized along with it. The coil slows the vapor, and any water will condense out. Ammonia vapor continues on up, and water condenses & trickles on back. Ammonia goes through condenser, it cools, and leaves as a liquid.
Ammonia liquid goes through small orifice and joins nitrogen vapor. When checking your fridge's temperature, monitor food storage area, not freezer. Thirty eight to forty is ideal. Below that, lettuce freezes. Above that, food won't be preserved properly.
Venting is critical. If fins aren't clean and clear, fridge will stop working. Birds nest, mfgrs left too much insulation, something falls on top of fins, etc -- all can cause failure.
Fridge Problems. Is it turned on? Thermostat properly set? DC power? Most of the new ones are automatic. Circuit board will typically run on DC power. If your battery gets low, your fridge will quit. Intermittant outage...check voltage to fridge. Sometimes the RV parks have inadequate voltage -- which can play havoc with appliances.
Any appliance with a board that fail to run: turn them off and back on again. That's like doing a "reset".
[Makes a BIG point throughout lecture: Fully explain symptoms to service tech.]
Fridge won't cool: First -- Is there heat to boil the vapor? If there is heat, check for venting. Birds next, something blocking venting. Could have failed cooling unit. Often freezer works, but not food compartment. Same whether on propane and electric. Usually cooling unit problem. Can be a thousand bucks to fix/replace, and few people qualified to do this sort of job.
When measuring levelness of fridge, measure at bottom of freezer floor.
Travel w/propane on for fridge? It is NOT advisable. Mfgrs say six hours off should result in an increase of only two degrees. If you're constantly opening the fridge though, that can impact it. Most new fridges have gone away from DC power source b/c of big power consumption.
Which is better -- Propane or AC? Should be no difference.
Some fridges start to frost up inside. Door gasket, or self defrost mode. If tube with crimp on (looks like its closed off). Sometimes tube is "open", so air is getting into fridge compartment.
Water Heaters:
AC, propane, motoraid. Okay to run AC and propane at the same time. Can give you faster recovery time. Motoraid problem is it's not thermostatically controlled. Can produce dangerously hot water. Esp tough on kids, grandchildren.
Two types...alum and steel lined tank. Atwood aluminum tank. Suburban steel lined tank. Anode rod is in steel tank only, to prevent electrolysis. Newer ones are in the drain...easily removed and inspected when you drain the tank. Atwood offers aftermarket anode rod, but they're useless.
Pressure/temperature relief valve. Good idea occasionally to open them and let them snap shut. Air gap should be at the top. If air pocket is gone, let air in. Flush monthly. Don't run the water heater electric element without water in it!