House Calls with the RV Doctor
By Gary Bunzer
May 2005
Annoying Ammonia
Dear RV Doctor:
Being a rookie RVer, I accidentally did not have my motorhome fully leveled while camping and, therefore, I now have a leak in my RV refrigerator. I am getting that wonderful ammonia smell when the door is opened. How hard is it to remove the refrigerator? I live in a small town. Would a local mechanic be able to help me? I am guessing the refrigerator is ruined. Will the refrigerator need to be removed right away?
Naomi Larocque
Seattle, Washington
RV Doctor: Naomi, obviously because of the leaking ammonia, the refrigerator is rendered inoperable. The entire cooling unit will have to be replaced. The average life of a cooling unit is about 10 or 15 years.
Unless you have a refrigerator that was built prior to about 1983, it is unlikely that the off-level condition was the cause of your problem. Around 1983 the construction of the heat exchanger at the boiler was changed dramatically to make it practically impossible for an off-level condition to lead to a damaged cooling unit. Today, and even prior to 1983, the most likely cause of a hydrogen and/or ammonia leak is the chemical reaction of the ammonia deteriorating the ferrous pipes. If the crack is situated at or near an exposed section of piping at the rear of the refrigerator, a bright yellow residue usually is visible. If the leak is in a section of pipe hidden by insulation (the more common occurrence), you may not see it. But any indication of an ammonia smell confirms a leak.
The first thing to be concerned about is ridding the ammonia smell from the motorhome. Be sure you open all the windows to air the coach out and refrain from using the RV until the odor has dissipated. Ammonia can be quite hazardous.
You have several options with regard to replacing the cooling unit. Most service centers give owners the choice of a lower-cost refurbished cooling unit with a shorter expected life or a new cooling unit that has never been in service, which means all of the piping is factory fresh. The entire replacement can take anywhere from two to four hours to complete, depending on the model. Cooling units cannot be repaired in the field “” they must be replaced, and this is not an inexpensive venture. Oftentimes RV owners must contemplate a third option “” a complete refrigerator replacement versus the cooling unit replacement. It depends on the age of the refrigerator and how fond you are of it. With units around eight years old, or older, seriously consider replacing the refrigerator. You will have a new unit warranty and all-new parts.
It’s best to let the service center remove the refrigerator and only allow a competent RV service technician to perform the replacement. Oftentimes the refrigerator will not fit through the entry door without removing some components and/or the entry door itself. In some cases, the cooling unit is replaced inside the RV.
Jilted Gen
Dear RV Doctor:
We have a Winnebago Adventurer. Our generator has 150 hours on it, and it will start only if we manually hold the lever to keep the idle up; otherwise, it dies. We have changed all the filters. Have you any other suggestions?
Jan Carbone
Temecula, California
RV Doctor: Jan, from your description, it appears that the choke, the carburetor, and/or the governor are out of adjustment. To be sure, the generator must be connected to a specialty device called a load bank. This tester will enable the generator to be set up properly while a varying, though measured, load is applied. Adjustments should be made only while the generator is connected to a load bank. Perhaps someone tried to adjust it without one; this is a very common occurrence. Unfortunately, it is not possible to tune a generator engine by ear. Every mechanical adjustment on the carburetor and governor will yield an electrical response that will affect the operation of the generator as well as the output voltage and frequency. Some, but not all, RV service facilities are equipped with a generator load bank. It will be necessary to call around and find a shop with one in its tool crib. Many shops have a load bank, but their technicians may not be trained to fully appreciate its value when setting up or tuning up the RV generator. No tweakin’ without the proper tester.
You do not mention whether the generator is gasoline powered, but if it is, I also would have a technician check to determine whether the oil is badly contaminated with gasoline, as the problem this creates sounds similar to what you describe. You also don’t mention the brand, but many Onan generators are equipped with a low oil pressure switch that will inhibit engine operation following the start cycle if that circuit is incomplete or if the pressure switch is loose or defective. A technician should check the wiring harness connectors behind the start panel on the gen set. Vibration may unseat a wire in any system, such as ignition, choke, or oil pressure.