Dwight and others,
Believe it or not, there actually is a tiny spider which will fit through a propane pilot orifice. It is attracted by the odorant used with propane. When the system has been left idle for a season, the spider enters through the pilot orifice, lays it's "cocoon" and leaves. After the baby spiders hatch, they also leave. The porous cocoon which won't fit through the orifice has then been left behind. Some gas does make it through the cocoon and one can often even get a small flame but it is usually not enough to heat the thermocouple. The cure is to remove the pilot gas tube and orifice, and either blow it out with air or flush it with water. Do not try cleaning the orifice with any object harder than a human hair or soft
paint brush bristle. It is fragile and the size of the opening is
critical to your fire safety & must not be enlarged. Once it is all dry, reinstall, check the joints which you have disassembled with soapy water (when you have got pressure present) to make sure there are no propane
leaks. Congratulate yourself after it stays lit and there are no
leaks.
Wise counsel... If there is
any doubt in your mind about your ability to accomplish this without burning up your prized RV, then have a qualified RV serviceman do the cleaning (they are supposed to have liability insurance)!! The monetary cost to you may not be worth the gamble, you are the judge.
I serviced propane furnaces for 25 years and this was an annual
fall ritual when the weather turned cool. RV hot water heaters may suffer the same ailment.
Again, a little knowledge may be a dangerous thing, and gas leaks of any kind will not be forgiving and the consequences may very well be
final.
You've been given contents in your head, please use them wisely to enjoy years of RV'ing pleasure,
Kurt & Ann K.