I just installed a Honeywell T10 Thermostat to replace a Honeywell T5 that was professionally installed with a brand new HVAC unit four years ago.

The HVAC at this home is a bit unique in that it is forced air electric heat. So essentially a coil on top of a blower. We also have Central AC coming through the same blower, with a condenser outside.

When I removed the T5, I re-installed the new T10 with the exact same connections/wiring pattern as the T5. In fact, I am pretty sure I didn't even need to change the wiring plate and the T10 would have plugged right into what was there for the T5.

Anyways, before the change, the fan would stay on for an additional thirty seconds after the heating cycle ended. Now with the T10, I can't get it to stay on after the cycle ends. I have went into installer options and set both AC and heat to have a thirty second run time after the cycle ends, but no luck. The coil and the fan shut off at the exact same time.

There is a setting where it asks if the fan is "equipment or thermostat controlled" to which I have set at "equipment". Do I perhaps need to change this to "thermostat" controlled? Any other settings anyone can think of that would remedy this?

  • 1
    Does the manual fan mode work?
    – KMJ
    Dec 6, 2022 at 18:36
  • Yes, just tried by switching to "on" rather than "auto" and it came on.
    – absentx
    Dec 6, 2022 at 21:23
  • I don't see any other settings that would apply. If you set 2010 correctly the manual really makes it look like that would do it.
    – KMJ
    Dec 6, 2022 at 21:40
  • Just talked to my HVAC guy who installed the original unit/t-stat. He wants me to try telling the thermostat it is a conventional forced air (not electric) as he wonders if that setting is just telling it to shut off when complete. Will report back.
    – absentx
    Dec 6, 2022 at 22:43
  • 1
    I've got nothing then. Wish I did - I went through the manual and still didn't have enough to compose a solid answer.
    – KMJ
    Dec 7, 2022 at 18:05


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