Thermostat Failure?

Problems related to residential installations.

Moderator: juster

Post Reply
Posts: 1
Joined: Sun Jan 08, 2017 6:55 pm

Thermostat Failure?

Post by schmuck281 » Sun Jan 08, 2017 7:05 pm

For some reason my thermostat a Honeywell Chronotherm III has decided that 65 deg would be a good temperature for my house. I have all the temps set for 72 deg. If it gets to be 64 deg the heat comes on but when it reaches 65 it shuts down. There are several settings, Wake, Leave, Return and Sleep. I have set all of them for 72 deg but it still thinks 65 deg is a good temp. I have even tried the Hold Temp function but it does the same thing. Thermostat is about 16 years old. Any Ideas? (besides buying a new thermostat)

Most Valued Contributor
Posts: 1019
Joined: Sat Jun 18, 2011 11:26 am

- Thermostat Failure?

Post by Freon » Sun Jan 08, 2017 8:12 pm

I would try a total reset. Remove the thermostat from the base where I assume you have 24 volts. Also remove the batteries. Let it set 30 minutes and then reinstall everything. If that doesn't help you can look at the PC board and see if there's an obvious cold solder joint or other circuit board issue. If nothing is apparent then it may be one of the temperature sensors.

New Contributor
Posts: 5
Joined: Mon Sep 11, 2017 8:44 am

- Thermostat Failure?

Post by morrislynch » Thu Sep 14, 2017 7:41 am

Thanks for sharing the great post.

Post Reply