Suburban SF-30F Furnace

Hi Everybody!

I have taken my trailer out of storage for the winter and went on a "shakedown" trip this weekend (Wooohoooo!!). Everything perfect - until chilly at 3am this morning I turned on the furnace.... Lots of blowing and clicking, but no ignition. I have brought it home and tried to look at it, but it is underneath the fridge, and I cannot see where the pilot light might be. I have tried turning it on again and went outside to the 2 exhausts holes. Smells like gas, and I can hear the ignitor rapidly firing away, but still no ignition.... Any hints, thought or ideas??

Thanks again for all your help!

Walt.

Hope this helps - Keith

Make sure the thermocouple is positioned properly in the pilot flame.

Another common problem is a bad regulator at the propane tank. A simple test will indicate if this is the case. Light all the stove burners and look at the color of the flame. The flames should be blue with little or no yellow color. If the flame does not change color then the regulator is probably working. A bad regulator could also cause problems with your hot water heater.

If your furnace fan starts you can assume that the thermostat is working.

Possible problems are insufficient air flow through the furnace a bad propane valve at the furnace or a bad regulator at the propane tank.

A furnace contains an internal sail switch, that senses the air flow. If the air flow is not sufficient then the switch will prevent the furnace from igniting and the fan will run but you will get no heat. A slow motor speed could be caused by a low battery or other low voltage cause such as a bad connection in the wiring.

Low air flow could also be caused by a restriction in the ventilation system. Check to see if any heat registers are closed or blocked. Some furnaces will not tolerate even a partial closure of a heat register. .

If you have an electronic ignition check to see if the two contacts are touching or are too far apart. They should be about 1/8 apart.

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You may need to get a small needle and clear the gas orifice. Sometimes spiders like to build nests there

Low air flow could also be caused by a restriction in the ventilation system. Check to see if any heat registers are closed or blocked. Some furnaces will not tolerate even a partial closure of a heat register. .

I can vouch for that one first hand,,, I covered the main bedroom register because it always gets hotter in there and was trying to force some hot air toward the front,,,,,, it cut off and would not start back for awhile.....

Thank you all for your help - I really appreciate it - and on a weekend!!. I am guessing I know the answer to this one.... I am going to have to undo the gas coupling at the front, after I have removed the front grill, and take the entire unit out to get to where the pilot flame is, correct? All I can get to now is the panel that covers the bladder looking air ducts - and the unit is hard plumed so will not allow for additional bending or kinking.

Thanks again, this forum is priceless!!

I don't understand the pilot flame talk. Don't these furnaces have an electronic ignition that doesn't require a pilot flame??

Did you try switching to the other gas bottle? In cold weather a bottle that is low on propane won't have much pressure. Before trying to light the furnace make sure you have good gas flow by lighting the burners on the stove.

Do you have wasp covers over the furnace exhaust vent? They will keep wasps from building nest in the gas pipe.

Admin wrote:

Low air flow could also be caused by a restriction in the ventilation system. Check to see if any heat registers are closed or blocked. Some furnaces will not tolerate even a partial closure of a heat register. .

I can vouch for that one first hand,,, I covered the main bedroom register because it always gets hotter in there and was trying to force some hot air toward the front,,,,,, it cut off and would not start back for awhile.....

That's weird; I've doing this for years without problems.

That's weird; I've doing this for years without problems.

I did it almost every time we ran the furnace last year. Depending on where we were in the WC we covered one or more registers with our strip carpets or hassocks. No problems.

i had the same problem. could hear the ignitor clicking but the furnace wouldnt light. finally figured out i had a small pin hole in the wiring and it was clicking to the metal it was laying against. i just taped around it and it has worked ok the last couple of years.

watzinger wrote:Hi Everybody!

Lots of blowing and clicking, but no ignition. I have brought it home and tried to look at it, but it is underneath the fridge, and I cannot see where the pilot light might be. I have tried turning it on again and went outside to the 2 exhausts holes. Smells like gas, and I can hear the ignitor rapidly firing away, but still no ignition.... Any hints, thought or ideas??

Thanks again for all your help!
Walt.

Had the same thing, just kept trying to ignite, it was the regulator / tank selector in my case. The dealer changed both out and problem solved.

Thank you all for your help with this one! The problem is solved.... It seems when the propane tank gets close to empty, the pressure is not good enough to fire the furnace. I filled the tanks today, and it fired up without a problem.....

Thanks again!

I had the same thing happen. Low gas was the problem. Got alot of "hot' air once I filled them.

Walt,

Glad your problem was easily fixed. But just to make a comment on to an earlier post, these heaters do not have pilot lights. They are direct ignition, that is the clicking sound you hear, the ignitor trying to fire the burner (similar to your gas BBQ grill). If you do not have them, I highly recommend the wasp screens over the heater intake and exhaust...trust me...I know!

So it sounds as though there is a level in the propane tanks at which the stove will continue to work but there is not enough pressure/volume for the furnace to operate?

My stove is working fine but the furnace just clicks and then a brief puff of hot air from the exhaust vent followed by more cold air and the re-starting of the clicking of the ignitor(s).

Thanks,
Sean

Pcb boards on these heaters could also be a problem, sometimes they need a little clean and to rub a Lead pencil over the solder contacts this some times brings the board back to life.
Sean

While on the heating subject, does anyone use a small electric heater instead of propane during the not too cold nights? I haven't tried it yet in the cat, but in my previous TT it worked extremely well. I'd just turn on the furnace in the morning to warm things up a bit before the DW got up. The electric heater would hold 50° - 60° + inside with outside temps in the lower 30's. If it was really windy outside, then I'd sometimes have to use the furnace during the night. We like to sleep with it rather cool inside. You can always add another comforter.

I use a small electric heater with built in fan at times when in cool/cold weather. Turn it down pretty low during the night and then use the furnace during the day. Really cuts down on the gas use.

My heating systems includes a register in the pass thru. I am about to close that register. Cold weather is not a problem in this area. Anybody have some thoughts.