Furnace Wont Light

[PapaGNO]

Hi I'm experiancing a problem with my furnace not lighting. when i adjust the thermostat it will kick the fan on to purge the furnace i'm guessing but wont try to light. The fan will just continuously run. I know with my home furnace when the furnace will continue to run it is in fault mode. Is there a reset i could be missing or a fuse that could be the problem. Not sure where my fuse box is on the camper. I have a jayco Qwest 1999. The furnace is a hydroflame 1825 111. thanks.

[clutch]

Is this the first time you have tried to use the furnace this season? It may take a while for the gas to reach the furnace.

[PapaGNO]

Yes it is but we were having this issue last year when the fridge and stove were working at the time. I would think if it was trying to light i should here the gas valve click to try and open to light the furnace.

[Daytripper]

Go turn your gas off at the tank and then open the valve slowly and try to light, if that doesn't help then try to turn it off and back on for a minute or so about 10 times to get the air out. If it doesn't light check the exhaust for bees nest spiders etc.

It also might be things blocking your vents not letting the sail switch open the gas. Or the sail switch may have some spider webs or dust bunnies on it.

If the fan is running without timing out it sounds like a gas supply problem rather than a switch though.

Also you might check for kinked gas lines leading to the furnace.

[PapaGNO]

Ok thanks. I was thinking the sail switch myself because like I said it don't seem to be trying to ignite. The fan is just running continuously.

[Daytripper]

Originally Posted by PapaGNO

Ok thanks. I was thinking the sail switch myself because like I said it don't seem to be trying to ignite. The fan is just running continuously.

If it was the sail switch, the fan would stop after a minute or so. Sounds like air in the lines or kinked gas line, bad valves or something like that. Still check the vents and exhaust though.

[PapaGNO]

So I went and tried it again. I disconnect the gas line right before the the valve where it ties in behind the trailer by the motor. I could smell propane instantly and hear it being released. I also put my hand over the exhaust and seems to be good air flow. I also went inside the camper and put hand over register and seems to be good air flow. The fan will still just run contiuously without trying to ignite. Im thinking if it tried to light I should hear the gas valve clicking open or something trying to ignite. Will the fan cut back when it trys to ignite? if so it defineatly is not. but if the motor is not kicking out after a minute u say it is not the sail switch? Could it be the DSI board then not sending the signal to the gas valve to open and ignite?

[namusmc65]

Could it possibly be a bad control board? We had that go out on a brand new unit. In fact, It came from the factory with a bad board!

[Ali#1]

Check your hot surface ignitor or your pilot light .Usually when the fan runs constantly 90%of the time it will be a high limit switch. High limit switch should be located right above the burners it's going to be two wires going to it jump those two wires together and if the furnace ignites then replace hi limit switch.

[User Name:]

Originally Posted by namusmc65

Could it possibly be a bad control board? We had that go out on a brand new unit. In fact, It came from the factory with a bad board!

Thats what happened to us

[MikeeDee1]

THis is what happened to me. The alarm lp gas had cut my propane off. I had to pull the fuse for the circuit and air my camper for a second, for safety, then put the fuse back in. Someone else may have already recommended this.

[PapaGNO]

Perfect thanks I'll try that tonight when i get home.

[PapaGNO]

So I hot wired the wires to bypass the hi limit switch and the furnace light first try. Is there a reset for that switch or does it mean you have to replace the switch. Also if i'm to replace the switch from what I can see I would have to remove the furnace to replace. is this the case or can the switch be removed easier? thanks again everyone for your help.

[Ali#1]

Originally Posted by PapaGNO

So I hot wired the wires to bypass the hi limit switch and the furnace light first try. Is there a reset for that switch or does it mean you have to replace the switch. Also if i'm to replace the switch from what I can see I would have to remove the furnace to replace. is this the case or can the switch be removed easier? thanks again everyone for your help.

There should be two screws that hold the limits switch in place.
yes you can reset the limit switch but they're only $15-$20,but before you replaced check your furnace filter, fresh air intake filter if you have them. usually dirty furnace filter or obstruction to the fresh air intake will make the high limit switch to stay open.

[DieselX]

Sounds like you have it nailed down, but here's a good link anyway.

http://beamalarm.com/Documents/troub..._problems.html