Attaching lawn irrigation timer to hvac thermostat for fan

[iamdsc]

Help please! I would like to attach a lawn sprinkler irrigation timer to my thermostat so that I can automatically run the fan (without a/c or heat) for air circulation at various times of the day.

The reason for attempting to use an irrigation timer is that, apparently, even if I upgrade to a digital/timer thermostat, I still can't control the fan alone. (My current thermostat is an old-style White-Rodgers.)

The irrigation timer outputs a 26v signal (which in normal usage goes to a solenoid in a water line valve)....can I just run a wire from this port and splice it into the green (fan) thermostat wire (which I believe is 24v)?

And what about the 'common' connection? I certainly need to connect the irrigation timer's com port to another colored wire coming out of the thermostat. (I know nothing about wiring/electricity as you can tell.)

Thanks in advance for any help and comments.

[Greg O]

No, what you propose will not work, and it will surely fry something!

You can buy thermostats to control the fan. I have one on my wall right now, and the last thermostat I had did too. Many programmable residential 'stats will give you four time settings a day, allowing two separate periods to control the fan. The temperature set points can also be set up or down at these times.

Honeywell manufactures a nice touch screen thermostat, TH8000 Vision Pro that will do what you want, plus it can run the fan in a setting where it will cycle the fan 20 minutes and hour IIRC.

There is no need to cobble something together!

Greg

[iamdsc]

Thanks Greg for your prompt reply. I will check out the Honeywell solution. (I had earlier talked to the company with whom I have an a/c maintenance contract, and they had no clues how to help me!!!)

[HeatMan]

Drop a few bucks and get a VisionPro Thermostat from Honeywell. It has a 'circ' feature to randomly turn on the blower.