Home still heating after reaching set temp

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Old 11-01-15, 05:08 AM
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Home still heating after reaching set temp

My wife and I just purchased our first house and we're having an issue with the house getting too warm. We usually set the thermostat to 65 while we're sleeping when the unit reaches that temp it does shut off and there is no air or heat coming from the vents for example it cut off this morning but we woke up the thermostat was reading 73 . We have Another thermometer to verify the temperature. There is heat radiating from the return which is right below the thermostat is that normal or do we have a significant problem?
 
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Old 11-01-15, 06:27 AM
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Tell us whether the t'stat is digital or analog. All t'stats turn the heating source OFF when the selected temperature is reached. All t'stats have an adjustable circuit (anticipator) internally that turns the heating system ON some degrees below the OFF setting. Could be the ON circuit needs adjustment. Using the independent thermometer, record temperature when the heat source turns on and when it turns off from the T'stat and the thermometer and share it with us.
If the t'stat is located above the hot air register, this is bad. Usually the registers closest to the floor are heat sources. When the heat source is ON, the t'stat is being influenced more by the blowing air from the register than the still air in the remainder of the house. This would make the house cooler because the blowing warm air is satisfying t'stat turn OFF instead of the still air in the remainder of the house. Look forward to the info.
 
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Old 11-01-15, 06:44 AM
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Hi stefan and welcome to the forum,
In addition to bob's suggestions, the location of any thermostat can greatly affect its settings.

When you say "heat radiating from the return which is right below the thermostat", that isn't terrible, until you find the thermostat right above it. After the system turns off, the furnace and supply ducts are still full of warmer air and depending upon the configuration that air will be pushed somewhere by natural convection. So relocation the stat my help.

Also, forced air systems cycle the burner on and off under control of the thermostat. But the fan that circulates the air is controlled by another stat or timer which allows it to run longer than the burner, thus delivering some of the extra heat that remains in the plenum and supply ducts.

If you use your second thermometer and check the house air temp some distance away from that return vent, does it agree with the stat. I'm looking to see if the 73 is just above the return or the whole house temp.

Bud
 
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Old 11-01-15, 06:52 AM
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Sorry I'm at work right now it is a digital thermostat I took some temps in the other rooms they were reading between 68-70 while the thermostat was reading 73 I took the plate off of the thermostat and couldn't find an adjustment for the anticipator. It's one of the Honeywell programmable ones from Walmart I believe. The thermostat is located right above where the air is drawn into the unit not sure what the proper name is for it.
 
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Old 11-01-15, 11:20 AM
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Your thermostat does not have anything adjustable in it. Your thermostat was mounted directly above a return duct. That in itself is not bad but when the furnace shuts off.... residual heat from the furnace can and will rise back up thru the return duct and affect the thermostat.

That rising heat will cause your stat to register higher heat and stay off longer. The end result is the temps in the house would be cooler than shown on the stat.

Nothing to really be overly concerned about. You could move the stat to a different location.

If you had the stat set this morning to 65 and when you got up it was 73.... that's a different problem and would indicate a defective thermostat.
 
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Old 11-01-15, 02:57 PM
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The seperate thermometer was reading the same as the thermostat at 73 right in that locations is it the thermostat or the rising heat after shut off
 
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Old 11-01-15, 03:22 PM
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IMO, it is the rising heat after the furnace cycles off. When you turn the stat off, does the fan continue to run for a short period of time? If it does, feel the air coming out of one of the supply registers, it should get a little cooler and then the fan cycles off.

In any case, having your stat right above the return is not the best place. Do you have another place where you could relocate the stat, even if temporarily, to see what effect it has on your temperature swings?

Bud
 
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Old 11-06-15, 11:47 AM
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What kind of system is this? Electric furnace, heatpump or heatpump with emergency electric backup?

I only ask bc I have heatpump with emergency electric backup and unless the emergency coils are on the air coming out of vents is not that warm. Would highly doubt heat would ever radiate out of anything unless the compressor was still on or the coils remained on after the heat call was satisfied. Now it has been warm recently and my house is tight and insulated and the temp will rise a few degrees on its own sometimes. I thought there may have been something wrong before but all my equipment has been replaced recently and it still does it from time to time. If it's 60s out sleep with the thermostat on cool setting.
 
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Old 11-06-15, 02:05 PM
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Turn the fan on so it can circulate the warm air
 
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Old 11-07-15, 07:37 AM
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Fan keeps running

With thermostat in off position and fan at auto, fan comes on. Eventually it shuts off and then comes back on in a while. Only way to keep off is turning off at breaker.
 
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Old 11-08-15, 09:45 AM
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Heat sequencers often fail in the closed position causing the electric heat strips to be continuously energized.



If you have a heat pump or electric heat you very likely have a heat sequencer in the indoor unit.




Electric heat strips use a lot of electricity and if this is the case here this problem should be corrected quickly to avoid a very high electric bill.

Do you have a clamp on amp meter?
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The make and model number of the indoor unit would be of assistance.

High voltage is always present at heat sequencers.
 
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Old 11-10-15, 06:26 PM
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Sorry it's been warmer so no need for heat but the thermostat hit 75 when set at 65 this afternoon, even if the unit isn't running or can't hear anything as soon as you turn the switch on to heat the heat starts coming out of the return vent how difficult is it to replace the heat sequencer, it's a Bryant model it's about a 15 year old unit
 
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Old 11-10-15, 06:46 PM
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Unit information
 
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Old 11-10-15, 07:41 PM
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That isn't the right tag.

You will probably need to remove the panel to see the tag (nomenclature) on the heat strips.

The number off of the sequencer would be better.

 
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Old 11-10-15, 08:04 PM
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Sorry I'm a complete novice when it comes to hvac, I turned my ac on when I got home because it was 75 in the house then turned it off, it's been off for a few hours turned the switch to heat and I can't seem to feel any heat coming from the return like it has been since we had to start using the heat could it be a sign that the relay is still functioning but on its way out or a faulty thermostat as mentioned in an earlier post, I'll check it again in a couple hours to see if the problem is occurring again. (the outdoor temps have t been out of the 60s mainly 50s past few days)
 
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Old 11-10-15, 09:20 PM
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http://www.amazon.com/Uni-T-UT210E-C.../dp/B00O1Q2HOQ

A good clamp meter would help trouble shoot this problem.
 
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Old 11-11-15, 07:26 PM
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It looks like the programmable thermostat that I installed doesn't work with systems with auxiliary/backup heat, I know my system has emergency heat, could this possibly be causing the issues or am I just completely headed in the wrong direction? I'm contemplating using the warranty service provided with the home purchase, a lot of this seems over my head was just trying to figure it out myself.
 
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Old 11-12-15, 05:50 AM
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What thermostat do you have?
 
 

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