By Steve Savage, Mobility RV Service
There was a time when “burping” an RV refrigerator was a standard service technique. Burping has gradually fallen by the wayside, so only old-timers remember when it was commonplace.
Up until somewhere in the early 1990s refrigerator cooling coils — those coils you can see when you remove the exterior cover on the back of your refrigerator — used to block easily. Refrigerator manufacturers eventually modified the design and the problem is less frequent. It still pops up from time to time, and sometimes you can get lucky and save over a $1,000 on a new refrigerator using the burp method.
Coils most often become blocked when an RV refrigerator is left turned on while the RV is parked on a steep slope. When in that position for a prolonged period (hours), the rust preventive that circulates in the coils, along with the water, ammonia and hydrogen, form crystals. These crystals travel up and down the tubing until they block the smaller tubes and the refrigerator then stops working.
How do you know if your cooling coil is blocked? In a blocked coil, the burner tube will be very hot but the coils on the left side of the refrigerator (in the back) will not be warm at all. This will manifest itself after the refrigerator has been run overnight. Anytime you smell ammonia or see yellow or a yellow liquid on the bottom of the burner tube, you have a definite “leaker.” Your cooling coil has gone to heaven and must be replaced.
If the coils are hot on both sides of the back or you hear a gurgling sound and the refrigerator is not cooling, it most likely is a leaker. The coolant charge is likely gone, meaning you’re in for either a new refrigerator or cooling coil. If the refrigerator is very old, given the cost of new factory coil I would opt for a whole new refrigerator. I also only “recoil” with original factory coils, given the problems we and fellow techs have experienced with reliability from other sources.
If your refrigerator is not cooling and you find it is only hot on one side in the back, burping is worth a try. It does take a considerable amount of labor and time.
• Familiarize yourself with how to remove your refrigerator from the cabinet where it is installed.
• Allow the refrigerator to cool down, if you have been operating it, and remove the refrigerator. Place it on the floor of your RV. We use a heavy carpet remnant so as not to mar the floor. It will be heavy and awkward, but two strong men can do it without too much trouble. Mind you, we don’t even attempt this with one of the big four-door models.
• With the refrigerator completely disconnected, tip it gently onto its side in such a way that the side that was not heating up is down. The side with the burner tube will orient up. Leave it overnight and the fluids inside will redistribute. Historically, folks said to turn it completely upside down, but we have had equally good luck laying it on its side.
• Next day, stand it back up, plug it in using an extension cord, and extend the 12-volt leads so you have power to the control panel (eyebrow board) at the front of the refrigerator. Turn the refrigerator on.
• Allow two hours to pass, and if you are lucky you will find the coil that was not getting warm before is now becoming warm. You should have a cold freezer and the lower compartment will begin to cool. It takes almost a day for it to completely cool down. If this is taking place, the refrigerator coil is no longer blocked and you can reinstall it and leave it on.
The downside to this procedure is there is no guarantee the coil will not become blocked again in the future. Despite this dark cloud, successfully burped refrigerators often go on to have many more years of productive life. The upside is, if it works, you have just saved yourself well over $1,200 in replacement costs or the expense of a new coil and the labor to install it, so we try this procedure first.
Why don’t dealerships do this? Many techs are young and do not know this was routine in years past. Additionally, it is not possible to issue a guarantee with this type of service, so the owner has to understand it may not work. Of course, if it doesn’t, the refrigerator is already out and ready to be serviced or replaced, so the labor involved is not a total loss.