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EAB · 10-04-2006, 10:47 AM

I have a Suburban sf-30 heater that when you turn it on, the blower blows for about 30 secs then shuts off. You then have to turn the t-stat off and on again for it to do it again. My batteries are new and charged and I'm hooked up to shore power. Any ideas of what to check?

EAB · 10-04-2006, 10:47 AM

I have a Suburban sf-30 heater that when you turn it on, the blower blows for about 30 secs then shuts off. You then have to turn the t-stat off and on again for it to do it again. My batteries are new and charged and I'm hooked up to shore power. Any ideas of what to check?

Moder2 · 10-04-2006, 11:32 AM

Sounds like it is either not getting gas, and is timing out, or the high limit switch it tripping...

John

Ray,IN · 10-04-2006, 04:15 PM

Possibly the sail switch is defective. It detects air movement,if present. If there is no air flow the sail switch shuts the furnace off to prevent overheating.
Another possibility is corroded terminals on the PC board. Try un-plugging each wire, and cleaning the connections, one at a time, to avoid switching wires to terminals.

Joe-K · 10-05-2006, 04:06 AM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by EAB:
I have a Suburban sf-30 heater that when you turn it on, the blower blows for about 30 secs then shuts off. </div></BLOCKQUOTE>

If the fan is running for 30 seconds and shutting down, I'm assuming the burner is not lighting. You may want to observe the furnace from outside to listen if the burner lights or sparks. If it doesn't do either, it does sound as if the sail switch is stuck so the furnace is not recognizing the blower is running.

MO _ Jack · 10-05-2006, 05:50 AM

You may want to check out the attached link to review a service mannual

www.bryantrv.com

Jack

charliez · 10-09-2006, 03:27 AM

Mine did this. Turned out I had a dirt dobber nest right against the igniter. It's abit of work to take apart and clean but do-able. Make sure you get a screen vent cover to keep another one from getting in there.

EAB · 10-09-2006, 04:46 PM

Well I took the intake pannel off so I could root around in there and the first item behind the cover is the 'limit switch'. I just happened to have a jumper wire in my pocket so I jumped the two wires together and turned the heater on (side note: I had to do this before I went to work in the morning because I live in Phoenix AZ and the t-stat only goes to 90 degrees so the trailer was too hot when I got home). The heater worked normally at that point, the burner came on and the fan kept running, then it did the proper cool down when I lowered the temp. So off to the parts store for the $8.00 limit switch. The wife and I went to northern Az to try it out but the first night the heater worked for half the night then didnt come back on. The second night it worked fine. So I guess we'll just have to keep a good blanket handy and see what happens. Thanks for the help.

Stylin' · 10-18-2006, 04:08 AM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by charliez:
Mine did this. Turned out I had a dirt dobber nest right against the igniter. It's abit of work to take apart and clean but do-able. Make sure you get a screen vent cover to keep another one from getting in there. </div></BLOCKQUOTE>

This is good info; it seems that it doesn't take much debris around the igniter to keep these from firing. We've experienced intermittant operation with ours, and just written it off to dust, dirt, bugs, etc getting on and off from bouncing down the road. It's kind of a pain to remove the furnace to clean, and it's sealed so there isn't much you can do with it installed. Maybe it should become part of the spring ritual getting it ready for the season.