Getting things fixed, now for the furnace

[JohnnyG73]

I recently purchased a '94 StarCraft Leisure Star 27FB. When I checked out the TT everything worked properly. After I towed it the less than 10 mile trip to where I store/use it, the A/C and furnace would no longer work.

I posted on this forum a few weeks ago asking for ideas about what could have gone wrong. I just about had it nailed down to the thermostat but decided to climb up on the roof and pull the hood off the A/C unit. Glad I did. Turned out the shroud was slightly bent and the fan was stuck. After bending it back the A/C worked great. One problem fixed. I can return the thermostat I purchased because it's unopened.

Next I tested out the water system by filling the fresh water tank. The pump worked and I had running water without any leaks. The toilet flushed and I had cold running water in the shower (inside and outside) plus the bathroom and galley sink.

I then decided to open the bypass valves to the hot water heater. Water poured out the drain hole. I replaced the missing plug and now have no leaks. I flipped the switch to fire the water heater and it worked properly and had hot running water in a matter of minutes.

The water heater in my previous TT required lighting a pilot light, as did the oven and furnace.

This trailer only requires a pilot light for the oven.

The furnace is going to be my final hurdle. When I switch the thermostat to heat the furnace fan starts. When I turn the heat up the furnace does not ignite. It should light automatically right?

It is an Excalibur 8500-II series by Hydro Flame. I opened the outside door to the furnace and everything looks in order and there are not even any burn marks on the exhaust. It looks like it was never used.

Is replacing the igniter the best idea to start with or is it more likely the problem lies elsewhere? Thanks for any suggestions.

[Old-Biscuit]

Here is a 'Furnace Troubleshooting Guide' with plain language, description/explanation of components and pictures........LINK

T-stat contacts close sending 12V power to 'timed delay relay' which sends power to fan motor.
Fan comes up to speed and closes 'sail switch' which allows power to go thru 'HI Limit' temp device and on to circuit board.
Circuit board sends power to gas valve and spark electrode which lights main flame. Signal is generated by main flame which goes back thru spark electrode to circuit board proving main flame. Circuit board hold power on gas valve until t-stat contacts open.
Timed delay relay allows power to remain on fan motor until cool down cycle runs out

If sail switch doesn't make up from fan blowing air on the paddle which moves contacts in sail switch..no power to circuit board
If HI limit device is open...no power to circuit board
If gas valve doesn't open....no flow of gas to ignite.
No main flame lighting off.....no signal generated back to circuit board
Spark electrode not positioned directly over burner slot...no lighting of main flame
Spark electrode not gaped correctly....can't generate enough spark to light main flame (1/8" between rod and electrode tip)

HERE
is a service manual that covers your model

Probably just needs a good cleaning.....and checking of contacts/terminals tight and clean. Doesn't take much resistance to stop 12V from flowing

[CavemanCharlie]

Check the outside exhaust and intake vent for restrictions. Wasp just love to build a nest in them. Got a dollar that says your furnace is plugged up with a wasp nest. If you lucky your may be able to knock them off and suck them out with your vacuum cleaner. I once had to remove a furnace and then I dumped a whole coffee can full of wasp nest out of it after I did.

[Fred_III]

Try U Tube
http://www.youtube.com/results?search_query=furnace+troubleshooting

[jimw606]

This might help.

www.cigtree.com/pkk/hydro-flame-excalibur-8500-ii-series

[JohnnyG73]

Mandalay Parr wrote:
It might be the sail switch. Maybe stuck if not used often.

I'm sorry, afraid I don't know what the sail switch is. Is it easy to access and inexpensive?

[Mandalay_Parr]

It might be the sail switch. Maybe stuck if not used often.