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Tim H.
Tim H., HVAC Professional
Category: HVAC
Satisfied Customers: 3971
Experience:  Experienced in all aspects of HVAC, both residential and commercial.
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My Honeywell Pro Th4000 Series thermostat is giving me fits.

Customer Question

My Honeywell Pro Th4000 Series thermostat is giving me fits. It does not follow the program I set for it. The technician who installed it set the program. It worked fine at first. Then I made some minor changes (moved wake-up time from 6am to 6:30) and it totally confused the thermostat/furnace. The first day after the change, the furnace came on early and had the house at the designated temperature at 5am instead of 6:30am. The second day after the change it didn't react at all until I overrode it manually and jacked up the heat because it was so cold in the house. In the second instance the readout said the setting was 68 degrees yet the furnace was not coming on.

This is really crazy. Is it possible the thermostat only works if set on hours vs. on the half hour?
Submitted: 6 years ago.
Category: HVAC
Expert:  Tim H. replied 6 years ago.
Thanks for giving me the opportunity to help! I'm not sure how long it's been since you made the changes, but this thermostat has "Adaptive Intelligent Recovery" which means it learns over time how soon to turn the furnace on to have your house at a certain temp by the set time. It may still be "learning".
Here is a manual for this unit with more information on adaptive recovery.
If it still does not work correctly after checking all settings, replace the stat.