Furnace fan questions

When I use my wood stove it gets too cold for the pipes under the house, and they freeze, as not enough heat radiates through the floor. The crawl space is more drafty than I would like. When heating with the furnace, there is a register in the duct work that blows a little bit of heat into the crawl. My question, is whether its ok to run just the fan on the furnace, so it will move some of the heat from the house through the cold air return, and blow a bit of it into the crawl. It would also move heat around the house better. How long is it ok to run the fan on the furnace continuously? It is only 2 years old, I think its a Trane. One of the 92 percent efficient jobbies.

Help!

Joey

Our thermostat has a fan setting on it. We run our fan 24hrs a day and I haven't had to replace a motor yet.

Sure, there's no problem running the fan without the burner.

Yes, it's perfectly fine. I try to spend most of the summer that way, circulating cooler basement air up to the top of the house.

It uses electrons but won't harm the furnace unless it is really old. I had to replace two blower motors on our 1960-vintage Lennox unit, but that was a matter of socket wrenches, wire nuts, and $100-$150 for the motor.

Shouldnt a programable t-stat be able to cycle the furnace's fan without turning on the burner? If not I sure you could force it to do what you want.

Pimpish, why not run heat tape and insulation around the pipes like on the trailer? Expensive initial buy in but with a thermal switch and good wrapping it will never freeze. I am certain my trailer is cooler inside the skirting than your crawl space.

I have a crawl space under my kitchen, basement under the rest. When it's wicked cold out I stick a small oscilating heater into the crawl opening (18" sq.) and it helps a lot.

http://www.homedepot.com/webapp/wcs/stores/servlet/ProductDisplay?storeId=10051&productId=100665606&langId=-1&catalogId=10053&ci_src=14110944&ci_sku=100665606&cm_mmc=shopping--googlebase--D27X-_-100665606

My pipes froze twice and I don't want to go through that again! My "to-do" list this summer is to get in there and insulate. I have hot water heat, so I'm thinking about running a length of baseboard under the floor also.

I don't run the crawlspace heater when I'm not home and don't run it more than 48 hours without checking it. It's not a great house, but it's less great when it's burned to the ground.

Dan

My house is worth three times more burned to the ground than my investment.

John Brown wrote: My house is worth three times more burned to the ground than my investment.

Same here. This is what $32,000 would buy in 1978.

Wayslow wrote: Our thermostat has a fan setting on it. We run our fan 24hrs a day and I haven't had to replace a motor yet.

I have a townhouse with crappy vent routing and air flow, so I also run the fan 24/7 just to keep the air circulating. (My fan is a constantly variable speed, so it just idles along)

Funny that it's just the northeastern members who have a ready answer to any furnace questions. I wonder why that is.

I thought about the heat tape, but we just had a local place burn down because...of heat tape. I think Im going to run another set of wires to the furnace so I can run the fan.

Joey

Use sheets of foam to line all the outside walls in the crawl space from the inside, just remember to "open up" the vented areas in Spring.

Easy, cheap and quick.

joey48442 wrote: I think Im going to run another set of wires to the furnace so I can run the fan.

Doesn't your thermostat have a slider for the fan that says OFF-AUTO-ON ? "Auto" means the fan runs only when the thermostat calls for heating or cooling. "On" means it runs 24/7 until you turn it off.

Duke wrote:

joey48442 wrote: I think Im going to run another set of wires to the furnace so I can run the fan.

Doesn't your thermostat have a slider for the fan that says OFF-AUTO-ON ? "Auto" means the fan runs only when the thermostat calls for heating or cooling. "On" means it runs 24/7 until you turn it off.

It does, but the old thermostat wire is only two wires, so its not wired to control the fan independently. (I think)

Joey

If you have the heat on, set the thermostat all the way down to make sure it doesn't make a heat call. Then flip the Fan switch to ON. If the blower kicks on, then you can control the fan operation separately as is.

You can run the fan (providing the t-stat switch is wired) all you want. Unfortunately, running the fan without adding heat will "average" the temperature of your house with your crawl space even though your return is up in the house so you'll find yourself using a lot more firewood just to maintain the temp. Using house heat in the crawl space would be inefficient and wasteful. Insulating your crawl space from the outside air should keep temps just above freezing. 33 degrees is all you need. Take the opportunity to wrap your pipes as well. Be especially vigilant about pipes with upturns running through outside walls like a kitchen sink. The pipe will freeze right at the 90-degree elbow first.

Alternatively, most forced air gas furnaces have a timer that adjusts the time the fan will run after the gas shuts off. Tweaking that might let you pull the max amount of heat out of the firebox and into the house, thus saving money and your plumbing as well.

I know insulation down there is the main thing. Each summer so far Ive done some insulation, think Ive got it covered and then find out the cold is still getting in there somehow...

Joey