Furnace blows cold air

[guy99]

Hi all, we have a suburban furnace with electronic ignition. Until this morning it was working fine. This morning the blower works (blows cold air) but apparently the burner is not lighting - there is no heat either from the vents or outside at the vent/intake.

Any suggestions about what has failed?

I have had a little problem with the thermostat but I assume that if the blower is running, the thermostat is functioning (the thermostat has 2 wires to it).

[janetbjt]

when mine did that, the propane tank was empty and the blower would not go off, so unplugged power and switched tanks, then plugged back in and all worked fine. hope your fix is that easy (well...easy after i figured it out!)

[guy99]

Alas, we have propane.

[balrgn]

On occasion, in my Argosy 20' Class A, I have had to turn the thermostat down a couple time then back up a few minutes later to get it to ignite.

This the first time in a while you have turned up the thermostat?

[Alumi-Naught]

check your voltage at the furnace. If the voltage is loe the fan will not spin fast enough and the sail switch will not engage.

Mark

[eubank]

Sail switches also fail, especially in somewhat dustier environments, and usually result in just the kind of symtom that you describe. Sail switches are relatively cheap to buy, but somewhat more difficult to install. What we've found is that the old sail switch can generally just be blown out well with compressed air and expected to live until the next time around. (Our new spare sail switch has been sitting in its original box now for several years!)

Lynn

[Jim Clark]

Originally Posted by guy99

Hi all, we have a suburban furnace with electronic ignition. Until this morning it was working fine. This morning the blower works (blows cold air) but apparently the burner is not lighting - there is no heat either from the vents or outside at the vent/intake.

Any suggestions about what has failed?

I have had a little problem with the thermostat but I assume that if the blower is running, the thermostat is functioning (the thermostat has 2 wires to it).

Consider yourself lucky, summer will be here soon and you will want the cool air it is providing.

Thanks Jim

[guy99]

Originally Posted by Jim Clark

Consider yourself lucky, summer will be here soon and you will want the cool air it is providing.

Thanks Jim

Boy, wouldn't it be nice if it worked that way

[TomW]

Originally Posted by guy99

Alas, we have propane.

I wonder if it is there & not getting lit. In an unusal move for me, I will jump right to the punch line:

Start up the furnace like you normally do, and step outside to the furnace vent. Do you smell anything other than cold air?

Tom

[guy99]

Originally Posted by TomW

I wonder if it is there & not getting lit. In an unusal move for me, I will jump right to the punch line:

Start up the furnace like you normally do, and step outside to the furnace vent. Do you smell anything other than cold air?

Tom

Don't smell any propane.

[TomW]

Originally Posted by guy99

Don't smell any propane.

And this was from the outside vent?

Tom

[overlander63]

Now, for MY stupid question, did you turn the propane on before trying to run the furnace?

[TomW]

Originally Posted by guy99

Hi all, we have a suburban furnace with electronic ignition...

Do you hear the electronic ignition "clicking"

Tom

[guy99]

Originally Posted by TomW

And this was from the outside vent?

Tom

Yes.