ignitor points

[trumpwer]

We have done a lot of early spring camping this year, and its been chilly, so we have had to use the furnace more than every before. I have a problem with the ignitor points carboning up, some times after every use, to the point that the furnace wont light. I have to pull and clean the carbon off the points, then it works fine. Can someone tell me why, and what I can do to prevent it?

[TomW]

Two possibilities.

The first is that your pilot jet is running too rich, and the resultant soot is accumulating on the ignitor. The pilot should burn blue in color - yours is probably burning yellow (too much gas-to-air mixture). There may be an adjustment screw on the LPG control block. Trace the pilot gas line to where it screws into the control block. If there is a screw close by it with a "This screw was set at the factory for optimal performance" warning, you're in luck. Turn the screw in about 1/8 turn & check the pilot light color.

The other possibility is that the ignitor's outer coating of "high temp resistance" material has eroded away, and the 'carbon' you have been removing is actually the base material eroding away. A new ignitor would be the only reasonable solution here.

Hope this helps,
Tom

[thenewkid64]

Tom has 2 good points.

There is a third issue that was not mentioned. Gas pressure to the appliance itself. If there is not enough pressure in the piping or a restriction between the main piping and the appliance you can have the same issue as Tom covered in getting too much gas. The typical RV appliance requires 11 inches WC pressure to operate properly. This is a function of the regulator on the tanks to get to that pressure and maintain it regardless of demand. over or under by just a bit can cause flakey issues with the LP systems.