I have a honeywell chronotherm iv thermostat. I run a program all winter. For summer, I just hold a constant temperature; no program.

So far so good. I would like to also run the fan 24/7 during the summer. I push the Fan On button, and it starts up, but the next day it reverts to Fan Auto.

How do I make the fan stay on?

TIA.

There are a number of Chronotherm IV models. Here's the manual for one.
http://homeappliance.manualsonline.c...idRes=15115418
Read the "installer setup" part of the manual.
Find your manual and look for something similar.

Dave M.

On Thursday, June 21, 2012 5:53:20 PM UTC-4, Dave M. wrote:
There are a number of Chronotherm IV models. Here's the manual for one.
http://homeappliance.manualsonline.c...idRes=15115418
Read the "installer setup" part of the manual.
Find your manual and look for something similar.

Dave M.

Thanks for pointing me to the installer manual. My contractor did not pass that along, so all I have in hard copy is an end-user manual.

However, the installer setup table did not have a setting pertinent to my need.

Meanwhile, I think I've figured it out. Originally, I set the temperature hold, then later, as an afterthought, went back and toggled the fan from Auto to On. My intuition was that the fan-on state would inherit the duration of the temperature. Apparently not so. I think it is necessary to toggle the fan as part of the hold entry.

On Thursday, June 21, 2012 5:53:20 PM UTC-4, Dave M. wrote:
There are a number of Chronotherm IV models. Here's the manual for one.
http://homeappliance.manualsonline.c...idRes=15115418
Read the "installer setup" part of the manual.
Find your manual and look for something similar.

Dave M.

Thanks for pointing me to the installer manual. My contractor did not pass that along, so all I have in hard copy is an end-user guide.

However the installer setup table did not address my issue.

Meanwhile, I think I figured it out. Originally, I set a temperature hold and then later, as an afterthought, toggled the fan to On. My intuition was that the fan-on state would inherit the duration of the held temperature. That's apparently not the case. If I toggle the fan on when I set a temperature hold, it seems to stick.