Greetings, perhaps someone here can give be an answer to my mystery. I have two Carrier furnaces that were installed 2 years ago. Model 59SC2B. The thermostats are simple non-programmable Honeywell digital display models. Here is the mystery: Last night was a good example. The upstairs thermostat was set to COOL. The cooling temperature was set to 72 degrees. The actual room temperature was 69 degrees because it got down into the 30s outside last night. Several times during the night I noticed that the fan went on for a minute or two. (Don't know if compressor went on or not.) How can this be? It doesn’t happen often because usually the outside and inside temperatures are at or above the set cooling temperature. But it does happen in both units. I’ve had two opinions so far when I posed the question to local installers. One said it’s wired wrong and the other said it’s a bad thermostat. (I can’t believe two thermostats could be bad.) Any opinions here? Thanks.
AC seems to go on briefly when set temperature is higher than room temperature
tjm001
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Greetings, perhaps someone here can give be an answer to my mystery. I have two Carrier furnaces that were installed 2 years ago. Model 59SC2B. The thermostats are simple non-programmable Honeywell digital display models. Here is the mystery: Last night was a good example. The upstairs thermostat was set to COOL. The cooling temperature was set to 72 degrees. The actual room temperature was 69 degrees because it got down into the 30s outside last night. Several times during the night I noticed that the fan went on for a minute or two. (Don't know if compressor went on or not.) How can this be? It doesn’t happen often because usually the outside and inside temperatures are at or above the set cooling temperature. But it does happen in both units. I’ve had two opinions so far when I posed the question to local installers. One said it’s wired wrong and the other said it’s a bad thermostat. (I can’t believe two thermostats could be bad.) Any opinions here? Thanks.
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Some furnaces do have a relay that briefly engages the blower when power is supplied to the furnace. If there was a brief loss of power to the house, both blowers would start momentarily when power was restored. Since it was during the night you may not have been aware of the power loss.
Beyond that, there is not enough information to give even an educated guess.
Beyond that, there is not enough information to give even an educated guess.
There definitely was no power failure.
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Then beyond that, there is not enough information to give even an educated guess.
Thanks, I thought of that too. My thermostat is a Honeywell TH5220D1029. Is this one that does that?
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