Furnace will not run

cowboy_71 · 10-07-2010, 08:41 AM

We tried to turn on the furnace yesterday morning and nothing...no blower noise,nothing.... It worked last year...could their be a dirt-dauber wasp nest binding the blower fan?...but can hear nothing at all, how do I check this out?...Thankyou for any ideas...No hurry, its about 90 degrees out there this afternoon!...

SWAILES · 10-07-2010, 11:13 AM

Not happy to hear about the 90 deg temps we have been below freezing overnight

Check to see if your fuses/breakers are okay, then check to see if your thermostst is set to heat and if in fact it is sending voltage to your furnace it will be low voltage dc. Check to see that connections are good.

Chrisnan23 · 10-07-2010, 11:19 AM

the furnace control board works off 12 VDC so make sure it has power and as was said above check that the thermostat is sending to the furnace.

cowboy_71 · 10-07-2010, 12:02 PM

ok , there was a 15amp fuse blown but when I replaced it..still nothing...maybe its just too hot in there this aft, will try again in the morn...thanks, will let you know...

Korbe & Diana · 10-08-2010, 12:12 AM

The furnace will not come on if the room temp is warmer than the thermostat temp control setting.

cowboy_71 · 10-08-2010, 07:25 AM

Ok... tried again this morn w/ temps in the 40s..nothing, but noticed the fuse blew again..how do I get to the blower w/out removing the unit?...Im gonna try from the outside , I still think it might be frozen in place with a dirtdauber wasp nest......

Chrisnan23 · 10-08-2010, 08:55 AM

Most of the furnaces come out the vent for cold air return, not from the outside.

cowboy_71 · 10-08-2010, 10:17 AM

After removing the outside furnace return air cover plate I was able to barley see a small portion of the blower fan...it hada dirtdauber nest on the only part visible so with a flashlite and stiff wire I knocked the nest down...replaced the fuse, will try to run it in the cool morning temp... afraid there are more nestskeeping the fan from turning...hope I dont have to take the whole heater out, not sure how that would work out anyway...any other ideas?...will place a screen over the holes even tho its not reccommended...

Hunter11 · 10-08-2010, 10:21 AM

I think the top of the heater cabinet will come off to give you access to the inside workings of the heater without having to pull the whole unit it out.

I have run the screen covers (from Camping World)on the heater and water heater for years without a problem. In the South with the critters we have I don't see how you can avoid it. We also have screen material behind our fridge vent and the one on top of the trailer.

cowboy_71 · 10-09-2010, 05:56 AM

Another cool morning test run, another blown fuse...shouldnt the blower fan turn freely by hand if not obstructed ?...it doesnt yet so I think theres another nest in there.......

GaPete · 10-09-2010, 06:18 AM

All furnace fans I have seen turned freely. Could also have a frozen bearing?

Ridgeman · 10-09-2010, 10:51 AM

Same here. All the furnace fans I've messed with turn freely. The frozen fan would explain the burnt fuse. You need to pull the furnace and get into it to see whats holding it up. Your probably right about the critter nests.

cowboy_71 · 10-09-2010, 01:10 PM

I pulled the furnace and took the housing around the fan apart to discover not one but FOUR nests that kept the fan from turning...I also discovered that apparently the FW was built tightly all around that furnace

...Wow what a job...will test it tomorrow...

Hunter11 · 10-09-2010, 11:16 PM

You should probably check your water heater, AC and fridge area as well. Until we screened all those areas off we had the same issues.

cowboy_71 · 10-10-2010, 04:37 AM

Success, finally, after tweeking the wire connectors this morning for about an hour,we now have a working heater....what a job...Yes, Keith, youre right, we are going to put those screen covers in place...what did you use for the fridge vents? did you do a home-made one or is there a special device?...do you just use those a/c plastic covers or a screen on the a/c?...

Hunter11 · 10-10-2010, 05:00 AM

We bought a roll of fiberglass screen material from Home Depot and my wife cut it to fit the inside of the vent covers for the fridge and then she hot melt glued them in place on the back side of the covers. She did the same thing for the inside of the AC unit covers. It works really well and does not block air flow.

artgpo · 10-10-2010, 05:04 AM

These are for the fridge vents: http://www.pplmotorhomes.com/parts/r...ct-screens.htm. They also have specific ones for Suburban and Atwood water heaters.

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