Furnace runs when it shouldn't

We have a propane fueled furnace and a wood stove. We use the furnace to wa rm the house in the morning, then heat with the wood stove for the rest of the day. The thermostat is set for 70° for 6 AM to 8 AM, and then 60° f or all other times. We recently upgraded to a high-efficiency furnace, and find that the furnace runs several times a day for about 15 or 20 minutes e ven though the temperature in the house is in the mid-70s. We have reprogra mmed the thermostat several times and, checked the thermometer. The only th ing I can think of is that the furnace is in the garage which is unheated a nd generally is close to the outside temperature. Would the furnace run jus t to keep itself warm? I hate wasting fuel having it run when the house is already warm. What can I do to stop this from happening?
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wrote:

Put a timer on it and shut it off from 6 am to 8 pm.
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On 1/2/2015 3:43 PM, esh wrote:

stove. We use the furnace to warm the house in the morning, then heat with the wood stove for the rest of the day. The thermostat is set for 70° for 6 AM to 8 AM, and then 60° for all other times. We recently upgraded to a high-efficiency furnace, and find that the furnace runs several times a day for about 15 or 20 minutes even though the temperature in the house is in the mid-70s. We have reprogrammed the thermostat several times and, checked the thermometer. The only thing I can think of is that the furnace is in the garage which is unheated and generally is close to the outside temperature. Would the furnace run just to keep itself warm? I hate wasting fuel having it run when the house is already warm. What can I do to stop this from happening?

Makes me wonder if it's just the blower, or if the propane burner is running also?
Wonder also if the thermostat is on exterior wall? Some times the cold air blows on the back of the stat, and fakes it out.
Kind of have to get someone there during one of the mystery run times, and see what it is doing.
- . Christopher A. Young Learn about Jesus www.lds.org .
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On Friday, January 2, 2015 3:43:07 PM UTC-5, esh wrote:

warm the house in the morning, then heat with the wood stove for the rest o f the day. The thermostat is set for 70° for 6 AM to 8 AM, and then 60° for all other times. We recently upgraded to a high-efficiency furnace, an d find that the furnace runs several times a day for about 15 or 20 minutes even though the temperature in the house is in the mid-70s. We have reprog rammed the thermostat several times and, checked the thermometer. The only thing I can think of is that the furnace is in the garage which is unheated and generally is close to the outside temperature. Would the furnace run j ust to keep itself warm?
No and it should not be happening.
I hate wasting fuel having it run when the house is already warm. What can I do to stop this from happening?
Many thermostats have an indicator that shows if it's calling for heat or cooling. Does yours? If so, does it show "heating" when this occurs? It would seem that this is most likely a thermostat problem. Could be an intermittent short between thermostat and furnace too, or a problem with the control board on the furnace. If it's not apparent it's the thermostat, you could try unhooking the heat wire from the thermostat, it's usually white, terminal is W1. If it's a two stage furnace then you would also have another wire that calls for heat. If you unhook the heat wire(s) and it still does it, then you know it's not the thermostat.
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esh wrote:

Hi, Some furnaces have provision for running when return air gets too close to freezing temperature for example when furnace malfunctions. But return air temp. sensor has to be installed and connected to the 'stat. Maybe this is the case?
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The thermometer on the thermostat? Maybe the stat needs recalibrating? Why not set it to 50 for all other times and see what happens. Then try 40.

I had a girlfriend like that. She ran to keep herself warm. I wanted to do that but she woudln't let me. Come to think of it, she ran to her car and I haven't seen her for quite a while.

I don't know.
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Another reason I don't want someone else replacing my floodlight bulbs.
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Some of those programmable thermostats can be a pain in the ass to set. Maybe yours is faulty, even though it dont appear to be so.
Try this: Buy a cheap plain thermostat. About $15 at a home supply or even walmart. Or go on Ebay and you may get one for $5. Temporarily remove your programmable t-stat. Install this plain thermostat, and see if the problem stops. If it does, your t-stat is defective. If not, you have another problem. Thats cheaper than calling in a furnace repair guy. Maybe some friend of yours has an old t-stat laying around, after they replaced it with a programmable.
I actually got rid of my programmable t-stat. My schedule differs every day. I was constantly having to screw with that thing. I now have a non-programmable, but it has a "lock" feature. I can lock it at 60deg. But if I want to raise the temp, I raise it by pushing a button on a digital readout to say 70deg and lock it there, until I go away and lower it again. It's so much easier to use! It takes me a few seconds to change the temp, but that;s better than spending 20 minutes every few days fukking with that stupid programmable thing.
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snipped-for-privacy@spamblocked.com wrote:

Hi, What is the brand name of the thermostat? Hope not an El Cheapo one.
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On Friday, January 2, 2015 10:34:35 PM UTC-5, snipped-for-privacy@spamblocked.com wrote:

Or just disconnect the call for heat wire, usually white, connected to the W1 thermostat terminal, when the furnace is doing one of it's mystery runs. If it's a two stage, there would be two heat wires, one for each stage. Also, as I pointed out, many thermostats today have an indicator on the display that shows "heat on" or similar when it's calling for heat.
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On Fri, 02 Jan 2015 21:33:54 -0600, snipped-for-privacy@spamblocked.com wrote:

Easier and cheaper - just put a switch in the line or disconnect the 'stat

If it's not programmable what would it need a lock for?? It's not going to change. Programmables have a "program over-ride" that over-rides untill the next program event. It also has a lock button for the over-ride, and a "run program" to return from the over-ride.
What would a lock do on a non-programmable?
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On Fri, 02 Jan 2015 23:33:56 -0500, snipped-for-privacy@snyder.on.ca wrote:

I didn't understand that at first either. If I chznge the temperature, it is temporary. For example, if it's set to 60 and I change it to 70, it will heat to 70, then it goes back to the last setting (60) Whatever was the setting the last time I pushed the LOCK button, is the default setting. So, in this case it will heat to 70, but them resorts back to 60. However, if I push "LOCK" after changing the temp to 70, then 70 becomes the default.
I guess in a way, it is programmable, but to a much lesser degree than the ones that need to be set for each day of the week and for different hours.
Most of the time I leave it set around 60, but if I come in from outdoors and have a chill, or if I want to take a bath, I can raise the temperature and dont have to manually set it back to 60 afterwards.
For my needs, that saves fuel, because I often fall asleep after a bath, and would not always remember to lower the t-stat if it was just a plain one.
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What have I have ever done to you that you post like this?
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es> We have a propane fueled furnace and a wood stove. We use the es> furnace to es> warm the house in the morning, then heat with the wood stove for es> the es> rest of the day. The thermostat is set for 70° for 6 AM to 8 AM, es> and es> then 60° for all other times. We recently es> upgraded to a high-efficiency furnace, and find that the furnace es> runs es> several times a day for about 15 or 20 minutes even though the
Some Furnace Run no mather the setting in this case it's probaly a equalizing Temperature or Humidifyer , just check ! it's possible if humidifyer the furnace Heat !
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Okay. Thanks.
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Thermostat heat anticipator?
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On Sunday, January 4, 2015 4:14:00 PM UTC-5, snipped-for-privacy@gmail.com wrote:

Anybody notice that with so many of these one shot wonders with alleged mysterious problems, we never hear from them again?
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snipped-for-privacy@gmail.com wrote:

Hi, Most digital 'stat anticipator is AI based. Did OP mentioned where the 'stat is mounted? Outside facing wall or interior wall? Oren raised this issue already.
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Tony Hwang:
Over/undershoot on many digital stats can be controlled with a firing length setting in the menus. Usually "1" "2"(medium good for most) or 3(longest firing time).
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Artificial intelligence - aka "almost smart"
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