Dometic furnace sail switch rehash/update

[tburrill]

Brenda from FWC has told me repeatedly that altitude might be my issue with my furnace not staying lit. Since I live in Truckee, 6,000 ft, and I enjoy camping in places higher in elevation, I would like to try increasing the ignitor gap. How do you increase the ignitor gap. I do not know where the ignitor gap is located. Thanks.

 

[Wallowa]

Brenda from FWC has told me repeatedly that altitude might be my issue with my furnace not staying lit. Since I live in Truckee, 6,000 ft, and I enjoy camping in places higher in elevation, I would like to try increasing the ignitor gap. How do you increase the ignitor gap. I do not know where the ignitor gap is located. Thanks.

I think you need to talk to someone else at FWC.... "altitude might be my issue" does not answer the question....6K is nothing...and we have used our '16 Hawk appliances at 11K with no problem...

Perhaps somebody on the forum can suggest a tech at FWC to answer your questions...Stan?

 

[J D]

FWC sells the sail switch that will very likely work for you. It did for me and has worked perfectly since. In process of buying that switch
I spoke with Brenda who confirmed it was the 33081 model.

Based on what I've read, there were a batch of malfunctioning sail switches. I got one of those I think. But now, after installing the new switch, the furnace ignites as expected. I do have a spare switch too just in case tho

Things to do:
1) Get a new sail switch. Dometic Furnace Sail Switch - Four Wheel Campers
2) Remove the foil duct that's right behind the grate where warm are discharges.
3) Be certain the return air intake isn't covered or blocked.
4) Turn propane tank main valve on very slowly.

FWC webpage has helpful videos. There's one there on propane tanks I found helpful.... There are more videos on FWC YouTube channel. Go there then from the FWC channel search "sail switch". There are two videos listed that are specific to the switch and furnace troubleshooting.

 

[Wallowa]

Thanks for reposting these videos...hope I can remember the steps on the road if needed! My 'old' memory fades in and out...

Never did understand the issue of altitude with a furnace failing to start...lots of speculations but nothing definitive that I have heard..you know, air density and oxygen Pp...seems to always come back to a weak or defective sail switch..I guess if insufficient mass of air is not pushing on sail switch it will not trip it and complete the ignition it is possible that altitude [mass] and perhaps an obstruction from the foil behind the grill on the inside could decrease the flow...

Ignition not occurring due to no spark and not due to not enough oxygen...hell I don't know!

Ps...Yes, I carry a new sail switch...

 

[craig333]

Much easier access than my old suburban furnace but since it still works I won' t complain. Now I know what people are talking about when they mention the access door. Mine has no door.

 

[Outnabout]

Are these furnaces that are later than 2015? I haven’t had these issues. Thanks.