RV REFRIGRATOR

B OUGHT A USED SLIDE-IN CAMPER ref doesen't work heating element works. I have heard take ref out turn up-side down shake it all around. Sounds like fun on a date!! Any body have experience with older rv refrigerators??? To be tractor related the camper is setting on the trailer I haul tractors on. Seriously guys need some help here. THanks Bill.

I have heard that also, tip them upside down for 24 hours, then right side up for 24 hours, make sure its level, and it should work!

My brother worked in refrigeration for 15 years. Rv type refrigerators use amonia and water, not refrigerent. they may have setteled out. turn it upside down for 3 days. then turn it right side up and try it. if it does not work then, it has a leak. replace it

Also, the older units had to be pretty level, and are very slow to get cold, slow as in a day to get cold. They do better on gas than on electric.

So, geezer, you're saying ammonia is NOT a refrigerant??? HMMMM?

Wonder how the adsorption cycle cools, then?

The absorption refrigerator mixture consists of ammonia (refrigerant), water (circulation accelerator & ammonia coolant), hydrogen (absorbent), & sodium chromate (acid neutralizer).

When the unit is setup for a period the water & ammonia separate in the absorbent tank and other minor areas in the system. They have to be mixed in order for the water to circulate the ammonia. Fairly level position is important in stationery operation as gravity is part of the circulation process.

Turning upside down drains the ammonia & water to the evaporator through the system resulting in some mixing. Turning back upright helps mix in the other direction. Allow time for the mixture to drain back to the absorbent tank before heating.

Small RV refrig requires about 6 hrs per position. Longer than that, the drain is completed and mixture begins separating again. When heat is applied, for about 10 mins listen for liquid movement or evidence of cooling at the expansion point in the evaporator. If none, shutdown the heat. Sometimes takes a couple of turnover cycles but often other problems involved. When circulation starts, mixing snowballs and and it will be up to normal during the first temp pulldown.

Make sure the heat path (chimney) is unobstructed for good draft elect & gas. Gas burner adjustment/cleaning may be needed. Prove out on electric first.

Joe

I ment that it used amonia and water, not the more conventional, modern refrigerant. my bad

I pulled a nonworking refrig from a 1976 RV and used the tipping over process and had good luck with it. I let it sit overnight upside down, then hooked it up to 110v to test it, before putting it back in. Has been 4 years now and continues to work. With the cost of a new refrig and the old age of the camper, I was very happy to get it working again.

Neighbor Wilson, having owned RV's for over 30 years Been there done that lol

Running them off level for sustained periods IS A MAJOR ENEMY of RV Amonia absorption type of RV fridges. If they are ran level and no leaks develop (NOT usually a problem) they can last like forever. (seems like if off level the sodium chromate dont drain properly and can clog up the tiny tubes????????)

Another problem Ive encountered is fine rust particles developing inside the burner flu assembly which hastens heat transfer PLUS can settle inside the LP burner. GET THAT HEATER FLU ASSEMBLY ALL CLEANED OUT, and the LP orfice burner assembly, I use my air compresor and a vacuum cleaner

Once the flu heat assembly is all cleaned out, Id to the upside down thing noted above and see what happens, remembering in this hot weather it can take a few hours for them to cool down.

If all else fails theres a dude up in Greenwood who repairs them and sells refurbished units, I think its called "Etters RV", a small home shop mom n pop operation with fair prices and good service

When you get that trailer under construction give me a ring, I will come down and "supervise" lol

John T (Just North of you)

Yo Joe, is it correct that running them off level is BAD because the sodium chromate dont gravity flow back down correct and can cling to and obstruct the tiny tubes??? If so can the upside down thing help that condition???

John T

Only thing I'd add is to rod out and vacuum out the vent. If it has been sitting, it is probably plugged with wasp & mud dauber nests, and spider webs. Won't run if it can't vent.

Let us know how it goes.

John, Depends on how long and how hot the boiler got. When it is run out of level enough to impede gravity flow, the ammonia & water mixture collect in other areas of the system instead of gravitating back to the boiler.

The liquid mixture level in the boiler drops causing a rise in temp of the remaining solution. The water in the ammonia solution begins to vaporize with the ammonia leaving the boiler and the sodium chomate comes out of solution and is left behind.

Eventually the boiler will go dry or nearly so and the sodium chomate changes state to a sludge that plugs up the perk tube and bakes hard as a rock on the boiler sides and up into the tube.

Joe

trivia: Albert Einstein helped design RV fridges