No Heat!

[tonyz]

So, in the middle of the night, the furnace kicked off and would only blow cool air. Propane tank was near full, so it wasn't that. Any ideas?

[TURBS]

How cold was it outside?

[tonyz]

45 or so, Had the same problem during the day close to 55 out

[caper]

How is the flame on the stove? I know you said the tank was near full. How long have you been running the furnace on the full tank? A 20# tank will last 3 to 4 nights when running the furnace.

[TURBS]

Just for kicks and whistles......... turn tank completely off then slowly re-open tank valve.

[tonyz]

Originally Posted by caper

How is the flame on the stove? I know you said the tank was near full. How long have you been running the furnace on the full tank? A 20# tank will last 3 to 4 nights when running the furnace.

stove fame is strong as ever, the fridge pilot was on and keeping everything cool. the tank was filled before I left and the furnace kapooted mid way through the first night.

[tonyz]

Originally Posted by f1100turbo

Just for kicks and whistles......... turn tank completely off then slowly re-open tank valve.

I will give it a shot, but don't understand what that would accomplish if propane is going to the other appliances as it should be

[Herk7769]

Are you in hookups?

Furnace requires a STRONG battery to run. Low voltage may not spin the fan hard enough to close the sail switch. Charge up your battery and try again.

Let me know if you are in hookups.

[tonyz]

Originally Posted by herk7769

Are you in hookups?

Furnace requires a STRONG battery to run. Low voltage may not spin the fan hard enough to close the sail switch. Charge up your battery and try again.

Let me know if you are in hookups.

Batt. was at near full charge, pushed by two Trojan 6V...same issue when I hooked up the generator. im really thinking it is an internal furnace issue, a switch of some sort or an igniter. anyone had a similar issue and a result that I can look at.

Great talk, thank for the hint, keep em comming

[rockwood06]

Maybe a bad sail switch, if the switch went bad the unit will shut down because this is what proves air flow, and or photo cell, if the photo cell can not see the flame because either bad or dirty it will shut the gas valve down and will not start back up....

[tonyz]

Originally Posted by rockwood06

Maybe a bad sail switch, if the switch went bad the unit will shut down because this is what proves air flow, and or photo cell, if the photo cell can not see the flame because either bad or dirty it will shut the gas valve down and will not start back up....

Is there an access to the photo cell and anything particular to clean it with? Now that it is home, I hooked up to shore, full propane, and I hear a click about every 20 seconds from the furnace until it shts itself off after about 3 minutes of no heat.

[rockwood06]

Originally Posted by tonyz

Is there an access to the photo cell and anything particular to clean it with? Now that it is home, I hooked up to shore, full propane, and I hear a click about every 20 seconds from the furnace until it shts itself off after about 3 minutes of no heat.

Clicking is good as long as it is sparking to light the propane, if no spark then the photo cell can not see the flame because there is none but do you hear the fan motor coming on, this would be the draft motor, this is what actives the sail switch, once the air is proven then the gas valve will open, but again no spark no flame the system will shut down after the draft motor runs for a few minutes to clear the unburn gas out of the fire box. For the most part all of the componets should be accessable from the out side of the camper.

One other simple thing to check go out side and make sure that the fresh air intake is clear, there are two chrome ports mark "HOT" on the unit one is an intake and the other is exhaust....with out it operating look inside of both of these ports, they must be clear from bug, bees or anything else.

[Dave_Monica]

Here's a link to download the Suburban furnace troubleshooting guide to help you out... Forest River Forums - Downloads - Suburban furnace troubleshooting

Dave

[brookside]

Thermocouple?

[tonyz]

Originally Posted by Dave_Monica

Here's a link to download the Suburban furnace troubleshooting guide to help you out... Forest River Forums - Downloads - Suburban furnace troubleshooting

Dave

Sweet, now I have some reading to do at work in the morning, thank you

[YoungKopernik]

I had a similar issue happen; heater worked fine for 2 days and then just would not light. It would cycle but not light. I was in the Mojave dessert the night before Easter so I figured it would take two more days to have a technician do any warranty service. I did all the advice listed above and then dove in.
I broke out the factory paper work(wire diagram and schematic) a multi meter and at 12am while the family slept I put on my head-lamp. My heater, probably yours too, is tight/stuffed in there the ducting is a pain and all the corners and edges are sharp. To make a three hour story shorter I went through: signal from thermostat, all the inner-locks(safety-switches) tapped on the solenoid valve(will be magnetic when energized), repositioned the igniter. I had this heater all but out and on the floor of the camper, lines were not quite long enough. I could not find any obvious problem and I start thinking about energizing(light it up) to really see what’s going on. Then my Own Personal Internal Safety Switch goes off and I give up. Had I been at home with no one else in the camper I would have energized it. So I put it all back together and gave it another try and it lit. I have no idea what fixed it and was/am nervice about it not working again but its never happened again. So problem could have been a sticky switch, sticky solenoid valve, a loose wire or igniter alignment.
If your good with a multi meter and don’t mind a few cuts and have a wire diagram and a schematic and a few jumper wires you can do it. I would recommend, do all the basics up to tearing it out and then take it in to a reputable shop.
In my last camper my wife put an umbrella over the exhaust duct outside and the heater had similar symptoms, would not stay lit. Umbrella got moved and all good, all but the umbrella it was ruined.
Good luck, let us know what happens
John

[KewlKamperz]

Originally Posted by tonyz

So, in the middle of the night, the furnace kicked off and would only blow cool air. Propane tank was near full, so it wasn't that. Any ideas?

We had a similar problem once. It turned out to be a mud dauber nest.