Wood Furnace fan doesn't run long

[cln]

My 18 year old house has a combination Wood and Electric pushed air furnace.

I'll start a fire and eventually the fan starts... typical and expected.

I question what follows. The fan will run for 1 to 2 minutes. In the beginning the ducts barely have time to warm up so the air isn't hot when it comes out. After a few minutes, the fire is roaring and produces plenty of heat. I even added a tiny 4" fan on the flue pipe to propagate the heat in my shop.

So if this 4" fan is enough to make a small difference in my shop, why isn't the furnace running longer at times?

I had the furnace inspected last winter/spring time. A fuse had popped. He checked it over and said there was nothing wrong with it.

Is there something I can do? I asked if the fan could be upgraded to a two speed fan. I figured that it could run on a lower temperature.

Any advice appreciated.

My last DIY thought was to attach 2x 4" fans on the duct outlet in my shop and having it on a 4-6 hour timer. Fans were free and both would cover a floor vent type duct elbow nicely... this way less of the heat would be wasted up the flue

[philoÂÂ]

I'd set it up to be thermostatically controlled to run whenever heat is present rather than just the first two minutes. A two speed fan is not a bad idea.

The way my furnace is set up...if the room temperature does not come up to the thermostat setting within ten minutes, it kicks into high.

[cln]

There is a thermostat for the furnace. One upstairs and one the Fan Switch

I do sometimes turn on the manual switch but if left on after the fire is out, it will only blow cold air...of course. I wish that switch would be upstairs instead then I would be less prone, and lazy, to turn it off.

The technician seemed to think otherwise about the two speed fan. But this is just one guys opinion

[Ed Pawlowski]

Is the short run by design? Or is it a bad thermal relay that is shutting it down? You can hook it up to run as long as s certain temperature is reached.

Is the fan taking heat from a heat exchanger or directly from the burner where it could cause an overdraft? Many possibilities here.

[cln]

I assume that the fan is blowing on it and cooling the Fan switch faster th an MY liking. I did talk to the furnace guy back then about it and he said it worked ok

I'll double check the Fan switch settings.

hmm, hard to answer this one since I can't see the entire inerds of the fur nace. it goes something like this. in a u shaped process; ?? ??

??Air flows by the 1 pipe flue ??, then through the filters,

? ? here sits the blower and motor ??then the unknown wood box ? ?that holds the electric furnace coils.

[micky]

You can tell it's the new generation, where every child wins a trophy, even when he comes in last, and parents don't whip their children anymore, and even the furnace air is treated more gently than it used to be.

We always had forced air furnaces, but now they just push the air. I guess APS** gets called if you try to force it.

**Air Protective Services. >

[philoÂÂ]

Though the two speed fan is optional, I'd find someone who can set it up so that the fan runs when heat is being produced rather than just the initial two minutes.

[trader4]

IDK what that picture is supposed to represent. You say you have a wood/electric furnace. This pic is of a gas furnace. The rest of the post is confusing too. You say the fire gets roaring, the fan comes on for one to two minutes, and then what? Fan shuts off for good? Fan cycles on/off? Without knowing more, how it's wired, impossible to say what's going on.

[cln]

Well Mike, maybe my furnace only pushes the air and should be kicked and beaten so it forces it instead!! I'll install a second blower! :)

[micky]

You'll get better heat that way. Just don't let the neighbors find out, or they may call the police.

[trader4]

If that's what happening, then the fan should be cycling on and off until the desired temp in the house is reached, but you don't say what's going on. If the fan is cycling, what temps are the fan switch set to go on and off at. What happens when it's using electric instead of wood? Too little info here to go on.

[Stormin Mormon]

air and should be kicked and beaten so it forces it instead!! I'll install a second blower!

let the neighbors find

Long as they can't hear the screams?

[Stormin Mormon]

starts... typical and expected.

1 to 2 minutes. In the beginning the ducts barely have time to warm up so the air isn't hot when it comes out.

produces plenty of heat. I even added a tiny 4" fan on the flue pipe to propagate the heat in my shop.

difference in my shop, why isn't the furnace running longer at times?

time. A fuse had popped. He checked it over and said there was nothing wrong with it.

could be upgraded to a two speed fan. I figured that it could run on a lower temperature.

the duct outlet in my shop and having it on a 4-6 hour timer. Fans were free and both would cover a loor vent type duct elbow nicely... this way less of the heat would be wasted up the flue

Sounds like you need a fan limit switch. Temp activated, blows when there is heat. I'd make some phone calls, and see if you can find a different repair tech.

[hrhofmann]

My grandparents home in NYC built about 1900 had a gravity hot air system. The pipes were huge, I am guessing 2' in diameter and went from the furnac e to the rooms on the first floor, and one big pipe went up to the center o f the second floor. Return air was down the open stairs all the way to th e basement. Circulation was strictly on the basis of the heated air rising . A fan to help circulation would have made a big difference. Coal was th e fuel.

[Stormin Mormon]

a gravity hot air system. The pipes were huge, I am guessing 2' in diameter and went from the furnace to the rooms on the first floor, and one big pipe went up to the center of the second floor. Return air was down the open stairs all the way to the basement. Circulation was strictly on the basis of the heated air rising. A fan to help circulation would have made a big difference. Coal was the fuel.

I've helped take out such "octopus" furnace. Often they had sand on top, in a cone shaped container on top. I remember helping carry out hundreds of pounds of sand.

They were very low efficiency, lot of heat went up the chimney. Each time, I'd hear back later, the fuel bill went way down.

[hrhofmann]

Octopus furnace is a perfect description. I remember having to crouch down to get under the pipes almost anywhere in the basement near the Octopus furnace.

[Stormin Mormon]

having to crouch down to get under the pipes almost anywhere in the basement near the Octopus furnace.

When I was a boy, those things really terrified me. Could not tolerate to be in a cellar with one.

[DerbyDad03]

A former co-worker's grandmother lived on the family farm. I visited with him a few times and he once showed me the coal burning octopus furnace. It had an electric screw-style shaft that would bring up one piece of coal per "fin" and dump it on top of the burning coal. It was one of the earliest auto feeds made.

How would you like a furnace like this...very pretty.

[pilgrim]

Because something is wrong with it. There is a temperature sensor that detects when the furnace is too cold to provide heat. When the furnace warms up enough to provide heat this sensor activates and causes a fan-control relay to pull in. When the fan-control relay pulls in it causes a fan motor to run. One (or more) of these three things is faulty and conks out after a couple of minutes.

Have your furnace repaired by someone who knows what they're doing. Maybe it was OK last winter/spring, but it's not OK now. I am taking your word for it that it's not OK now (you know, the fan craps out after a couple of minutes).

Something is wrong with your furnace. Get it repaired by someone who knows what they are is doing. Ask the repair person to rig the 4" fan on the flue pipe to run when the main fan runs.