House Calls with the RV Doctor
By Gary Bunzer
December 2006
Dear RV Doctor:
I have an older Thetford toilet and the bowl is leaking water. I took it to the repair shop, and they claimed there was toilet tissue in the groove. It held water for about a month while it was not in use. Then while I was camping this weekend, the water started draining out again. Any suggestions as to how I may fix this problem without having to take it back to the shop?
Betty Smith
Austin, Texas
RV Doctor: Betty, it’s actually quite common for Thetford toilets to develop this problem over time. The situation is caused, in most cases, by foreign matter becoming trapped in the slide blade groove, as your repair shop mentioned. It is possible they did not or could not remove all the debris inside the flushing mechanism groove. In severe cases, the mechanism must be removed from the toilet and disassembled, cleaned, lubed, and reassembled.
Before resorting to that unpleasant extreme, fashion a hook out of a coat hanger or a bent screwdriver that will reach into the groove to scrape out the residue. Take special care not to damage the rubber seals. One seal is located above the slide (see photo) and another is below the slide blade. Do this repeatedly until no more waste or tissue can be removed. Flush the toilet a few times, then lube the slide with a noncorrosive, petroleum-free Teflon-type lubricant or something similar. It takes a little bit of determination to remove all the debris. Perhaps your service facility did not exert enough patience the first time around.
To check your results, fill the toilet bowl with water and mark the level with a light pencil mark on the inside of the bowl. Simply let it stand for 30 minutes or so and see whether any water seeps past the slide blade. If it does, the only recourse is the disassembly procedures I mentioned earlier. Thetford does provide a packaged repair kit for this task that includes all the necessary seals, screws, etc. Unless the plastic slide blade itself or the internal cavity has been physically damaged, disassembling, cleaning, and lubing is usually all that is necessary, however unpleasant that task may be.
Oily LP?
Dear RV Doctor:
I replaced my propane regulator because the pilot for the water heater kept going out. When I disconnected the regulator, an oily liquid poured out of it. Can you tell me what that liquid is, and where did it come from?
Tom Clark
Redwood City, California
RV Doctor: Tom, that oily molasses-type gunk is residue from a combination of effects happening within the LP container. Chances are your LP container had been almost drained completely at some point as well as overfilled at another point, and probably repeatedly overfilled. Moisture in the container and the remnants of the odorant used to give LP gas its distinctive smell sometimes coagulate into that sticky mess when liquid LP is allowed to enter the regulator. This situation will quickly ruin the regulator. Remember, LP is stored as a liquid but utilized as a vapor. During an overfill condition, liquid will be force-fed into the regulator. If liquid is forced through the regulator and into the black iron pipe manifold, it could eventually find its way to the appliances and cause real havoc.
Have a qualified technician disassemble the output hose from the regulator back to where it meets the black iron manifold and inspect for that oily goo. If some is found, keep disassembling the piping until no more residue is located. All affected pipes, tubing, and/or hoses will have to be replaced. There is no effective way to clean out that mess. Hopefully, your appliances are still functioning okay.
Remember, never have the LP container topped off; never fill more than 80 percent. Most containers are now equipped with an overfill protection device (OPD), so, thankfully, this situation is not as pervasive as it was in the past.
I Want My TV
Dear RV Doctor:
I am having trouble with the TV reception in my motorhome. I have been told it is either the antenna head or the powered wall receptacle. How do I tell which is the bad part, other than buying and replacing each part until it works?
Mark Clement
Islip, New York
RV Doctor: Mark, the 12-volt power supply of the TV antenna actually sends 12 volts to the power head in the antenna. First, be sure the power supply is turned off; never connect or disconnect the coaxial cable with the power supply turned on. Up on the roof, disconnect the cable at the antenna head. With the power supply turned back on, you should be able to measure 12 volts DC between the center conductor and the braided shield on the coaxial cable. If 12 volts DC is not present on the coax, turn the power supply back off and remove the power supply and receptacle from the cabinet to gain access to all the connections. Disconnect the coax lead going to the antenna head and turn the power supply back on. If no voltage is present at the power supply output connection, check the incoming voltage to the power supply. If adequate voltage is coming into the power supply, but no voltage is present at the power supply connection leading to the antenna head, replace the antenna power supply.
If you can measure voltage at the connection on the power supply for the antenna head, either the coaxial cable is broken or the antenna head itself is faulty. Turn the power supply back off. Obtain a length of coaxial cable and bypass the existing cable. Run the replacement coax from the output of the power supply, out a window, and up to the antenna head. Turn the power supply back on once more. If you now have amplified and improved television reception, the existing coaxial cable has an open in the conductor, which mandates replacement. If the reception is not improved, replace the antenna head.
When replacing the coax, it will be necessary to route the cable from the cabinet that contains the power supply up through the roof and to the antenna head … or you’ll have to leave that window open all the time! And be sure to properly seal any cables penetrating the roof.