Intermittent gas flow to furnace

[kvgdvm]

Hi,
My new RV has an annoying problem. The furnace only works intermittently. Of course, when I take it to the dealership it works just fine. They already put in a new furnace control panel, which made no difference.

It appears to be a gas flow problem. The other propane appliances (stove, hot water tank) work perfectly all the time. But the furnace lights up properly sometime, but other times the fan just runs for a minute or so then shuts off. Once it does work properly it will continue to work properly.

Sometimes I can get the furnace to light up by fiddling around with the propane system. For instance, sometimes if I light a stove burner while the furnace is trying to light, the furnace will then light up - but not always. Sometimes if I light the furnace first before I light anything else it will light up normally - but not always. Sometimes if I shut off the propane tank, drain the system by opening a stove burner, the open up the propane valve again, the furnace will work - but not always.

It behaves the way one would expect if a flow check valve was malfunctioning, or possibly having some debris in the gas lines.

Any suggestions on what the problem might be, and where I should be looking?

[BigH]

Originally Posted by kvgdvm

Hi,
My new RV has an annoying problem. The furnace only works intermittently. Of course, when I take it to the dealership it works just fine. They already put in a new furnace control panel, which made no difference.

It appears to be a gas flow problem. The other propane appliances (stove, hot water tank) work perfectly all the time. But the furnace lights up properly sometime, but other times the fan just runs for a minute or so then shuts off. Once it does work properly it will continue to work properly.

Sometimes I can get the furnace to light up by fiddling around with the propane system. For instance, sometimes if I light a stove burner while the furnace is trying to light, the furnace will then light up - but not always. Sometimes if I light the furnace first before I light anything else it will light up normally - but not always. Sometimes if I shut off the propane tank, drain the system by opening a stove burner, the open up the propane valve again, the furnace will work - but not always.

It behaves the way one would expect if a flow check valve was malfunctioning, or possibly having some debris in the gas lines.

Any suggestions on what the problem might be, and where I should be looking?

I had a similar issue and found the flex hose to one of the propane tanks was kinked a little.

My stove would work fine also...I concluded that the stove needs more propane and the kink was enough to starve it sometimes but not enough to keep the stove from operation.

[kvgdvm]

I was able to follow the full length of the hoses and they are kink free.

There is however a valve that splits the propane to the different appliances. Does anyone know if this would have flow check valves inside, or if this is likely to be part of the problem?