furnace

[WINNE33]

Hello

I have a problem with the gas furnance. When I turn it on the blower come on but the gas or spark never happens. It turns off and then waits before trying again. My Winne is an 03 Adventure. Has any one had the cover off the back?
Richard

 

[Dave T-FRF]

Remove the 4 screws on the outer edges. There is no need to remove the screws around the exhaust & intake. Now pull the cover straight out. The exhaust & intake tubes have to slide out of the furance. Once that cover is off remove the cover by removing the 4 screws on the bottom of that cover. then lift that cover off. Once off you can see the furnace. If you have to remove the furnace. Turn the gas off at the LP tank. Remove the gas line off the furnace. Unplug the wiring. Remove the screw in the bottom center of the furnace. Now the furnace can be slid back & out.

 

[Stan Schultz]

WINNE33 -

Two important data items are missing. We need to know the manufacturer and the model number of your furnace.

Visit this link to see what I did with mine some time ago. (Our posting is about the 4th one from the top. Read the other postings, too.)

Also, if you bought the RV as new the dealer should have made sure you had an owner's/operator's manual for it. If you don't have one, you have several options:

1. Once you figure out who made it and the model number, search the 'Net for their website, go to their technical help page and try to find an on-line version of the manual.

2. Call the manufacturer directly and speak to their technical people. They should be able to mail you a copy, although they may charge you for the service.

3. Call an on-site repair place to come out and fix it for you.

4. Take your unit to a dealership and have them fix it.


I was told that the majority of furnace, start problems are caused by dirty contacts on the circuit board, so the very first thing to do is clean those contacts. If that doesn't work, you can pull the board and take it to a larger RV repair shop and ask them to test it. Many of them have equipment set up for this. Or, you can buy a replacement board and install it yourself on faith.

Best of luck.

 

[DAN L-WO]

i had a similar problem on my suburban SF-42 furnace. the fan would run, but the furnace would not light off. i checked the burner for debris, spider webs etc. no joy. i installed a new module board pn #520820 and it solved my problem. the board is located on the left wall of the furnace compartment and is easy to change. if memory serves, it cost me about $100 in apr 2008.
about a year before that i had an intermittent problem with the inside thermostat. the heater and ac would run, then shut off and not start again intermittently. the thermostat also cost about $100.

 

[Ptribbey]

Had the same symtoms with mine and it turned out to be a bad sail switch. This is a micro switch that is made with air flow from the blower. The switch was about $8.00.

 

[WINNE33]

Thanks Guys

Mine is a SF-42 and the key I think to my problem is Just the fan comes on without the smell of gas or the sound of a spark. Has anyone had touble with the "SAIL" switch?

Winne33

 

[WINNE33]

Thanks Pat

 

[WINNE33]

Pat

Did you fix yours yourself?

 

[dennis2-WO]

On my sf 42 sometimes just the blower would run all the time and no ignition. Found sail swith trip arm hanging up on blower housing. Filed some off of housing to clear arm. That was 2 rs ago no problems since.

 

[dennis2-WO]

Winne33,
Dave is right do not need to remove exhaust screws.

 

[WINNE33]

Sail sw seems ok. I checked for voltage at the sw and there is none. Ohms seemed ok to. Anyone know where to find trouble shooting info on the web. Or do we have a tech that can lead me in the right direction for a diy repair.

winne33

 

[rvcarpenter]

try:
http://rverscorner.com/furnace1.html#other

 

[WINNE33]

rv

That gave me a good uderstanding of how the sail sw works but what i really need is a drawing of the parts and where the sail sw gets its power. It must come from the limit sw and I cant get to it from the outside of the winne.It apperars to be behind the exhaust blower. I would like to check ohms across it.

 

[WINNE33]

Ok Fixed!!!!

took the back cover off of the furnance and removed black cover. 4 screws at bottom. Disconected gas line ,easy, after turning gas valve off at tank and lighting range to burn off gas in line. Disconnected power plug going to furnace. removed 2 screws holding furnace in. pulled furnace out. Checked limit sw that is located over at the far end It has the black and white wire going to it. Ohms ck was open. should be always closed. checked it a couple of times and it reset to the closed pos. FLAKEY. Went to local rv shop and bought new exact replacement. Reinstalled in rev order. Putting the furnance back in you need to place a couple of boards under it so you can slip the furnance back in. If not the furnance will drop down and not go to its pos. Take a look you will see why Again Easy.

Hope this helps Winne33

 

[JC2-WO]

So it was a defective sail switch?

 

[dirko]

Hi Ho: Sounds like a defective limit switch. That is different from the sail switch. When electronic stuff fails always check connectors, switches and relays. These mechanical parts fail more often that solid-state stuff.

Dirk

 

[WINNE33]

yea

I used to work for the big copying machine co. and the part I remember replacing most was micro switches aka "Sail SW." In my case it was the limit sw or better name overheat thermosat like in a home dryer. If anyone has a question send me a P M and I will try to help

Winne 33

 

[NeilV]

Originally posted by JC2:
So it was a defective sail switch?

I believe it was similar to one of these:

http://www.marksrv.com/suburbanparts.htm#ls

 

[mikwallace]

Thanks for all the input to this thread!!! I had similar problems with my SF42 and turns out it was the wire connections at the sail switch. A little corrosion!! I took the wires off the sail switch, cleaned the sail switch connectors and the wire connectors, put some of that stuff for dissimilar metals and put it back together and it started six time without error!!

thanks!!

 

[Lt46]

Re. pulling the SF-42

When you guys are discussing pulling the furnace... are you talking about pulling the fan cage/exhaust-intake ports etc. out of the metal box it lives in, OR are you talking about pulling the metal box with these components inside?
Here's a picture of mine; what I'm talking about is; on the left side, where gas line and electrical wires are seen, these come through a vented metal box. Is it this metal box that comes out or does the furnace disengage from this box for removal?