RV Doctor Column RV Doctor #301 Dear RV Doctor, I have an old 1983 Magic Chef, four burner stove in my trailer. I thought the safety valve was bad since it would not light. I'm beginning to wonder if the pilot is not hot enough to keep the bulb boiling so the valve would open. Is there a "secondary" stage of the pilot when the oven knob is turned past the pilot section? If yes, mine is not working. Steve Ger, (Bothell, WA) Steve, The oven thermostat control assembly attaches directly to the gas pipe manifold and allows LP to flow to the stove-top pilot, the oven pilot and ultimately, to the main burner assembly in the oven. Attached to the thermostat is the temperature sensing probe, positioned inside the oven. This is the portion of the thermostat that monitors the inside temperature and allows the thermostat to ignite the main burner when more heat is called for. Many times a thermostat is wrongly accused of being faulty when, in fact, the temperature sensing probe may simply be covered with cooking oils or grease, or even oven cleaner, and is simply not sensing the temperature correctly. Keeping this sensing element clean will eliminate many problems associated with false temperatures being suspected in the oven. After the thermostat calls for heat, here's what happens. Assuming the pilot flame is lit in the oven, when the thermostat is set to a temperature, in most cases, the oven pilot becomes slightly larger and begins to heat a thermal bulb attached to the safety valve. This thermal bulb, which is filled with mercury, expands a bellows in the safety valve and allows the main burner gas to flow from the thermostat to the safety valve and on to the main burner. That's why there is a time delay from when the oven thermostat is first set to a desired temperature until the main burner actually ignites. So you were correct in thinking there is a "secondary stage." A good way to tell which component may be faulty in a situation where the main burner will not ignite at all, is to carefully watch the oven pilot. While watching the pilot flame, turn the oven thermostat knob up above three hundred degrees Fahrenheit. Immediately, the stand-by pilot should expand and envelope the thermal bulb portion of the safety valve. If it fails to gain in size, replace the thermostat. If it indeed becomes bigger and engulfs the thermal bulb, then the safety valve is faulty and needs replacing. The positioning of the thermal bulb in the secondary pilot flame is crucial. It has to be in the fire in order to boil the mercury inside. However, if the oven pilot will not light at all, replace the thermostat itself. Dear RV Doctor, I have a 22-foot Nomad travel trailer. Periodically I would notice small amounts of water on the floor in front of the toilet. I have removed the toilet and noticed that the wax ring was not making a continuous seal. I have two questions; what is the correct removal of the plastic closet flange? Is it threaded onto the waste holding tank? Also what is the correct installation procedure? From what I can determine there is a wax seal between the floor and the closet flange and between the flange and the toilet. Your advice would be greatly appreciated. John Sentner, (Fall River, MA) John, The toilet floor flange may be connected to the holding tank by any one of three different methods. It could be, as you mentioned, threaded into a fitting on top of the tank, it may be cemented directly to a slip fitting on an ABS tank or it could be simply inserted into a rubber grommet positioned on top of the tank. There is usually a short piece of three-inch ABS piping between the flange and the tank and that too may be threaded or glued to the bottom side of the flange. Obviously you will need to inspect these points quite carefully to determine just how yours is attached. A flashlight and a mirror are sometimes needed to be sure. The floor flange, once attached to the tank, is secured to the floor with common wood screws to keep it from rotating. After the toilet is removed, use a putty knife to remove what's left of the wax ring. Be sure to clean all remnants of the seal so you can gain access to all the screws in the flange. Take note of the orientation of the closet bolts and be sure to reinstall the flange back to the original position so the closet bolts will still be in the right place to install the toilet. And be sure the flange lies flat to the floor. If the top of the tank is bowed causing the flange to lose its parallel orientation with the top of the floor, leaks could develop more easily. There is typically no seal between the flange and the floor, only between the flange and the base of the toilet. Always use a new ring whenever the toilet has been removed. I usually recommend a rubber ring instead of the wax ring. In the heat of summer and after some use, the wax ring has a tendency to soften, melt or move some, which can cause leaks as the toilet is used. Was the toilet a little rocky or did it shift at all before you removed it? Using the wax ring, if it was installed in cool weather and the closet bolts tightened correctly, there could be a chance of the wax ring softening and the toilet becoming wobbly unless the closet bolts are re-tightened during the warmer months. I sense there are less problems and certainly less mess with the rubber seal. It is also quite possible the three-inch down pipe from the flange to the tank was cut a little too long causing the flange to not lie flat on the floor. Rarely is it necessary to add a second wax ring to properly seal the flange connection. If the flange sticks up above the floor or is slanted and not parallel with the top of the floor, leaks cold develop. Dear Gary, The brown striping is peeling from around the outside of my 1994 Fleetwood Class C motorhome. Any suggestions for making it look better? Betty Jones, (Arlington, TN) Betty, A sad fact to realize is that constant exposure to the elements and the changes of seasons, RV exteriors take a lot of abuse. Even when properly cared for, UV bombardment and ozone contamination simply happens. At some point, all decal-type graphics on RVs will have to be replaced. You are at that point now. The glue backing has simply lost its inherent sticking ability and there is virtually nothing that can be done except look for some replacement striping. Perhaps your dealer can order the original size and color for you. Extended life can be realized for decals and other graphics by always using a full-coach cover when the RV is not in use. And by cleaning and protecting the finish regularly, two or three times a year. More often if you live in areas of high ultra-violet radiation or ozone producing zones.
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