said by marors1:
I am quite confused as to why you need to go downstairs to turn on the circulating fan. The thermostat (the square box with the silver wheel) is, as mentioned previously, the fan thermostat. It should be handling the job of turning on and off the fan as necessary as long as it is set to auto (usually that little white know is in the 'out' position to set it for that.
Why are you going through all of this trouble? If the fan thermostat is out, replace it. If you put in a relay, it will start up immediately upon a call for heat, and will blow cold until it warms up a bit, and will then shut off when the t-stat is satisfied and will not blow out the remaining hot air in the furnace. Maybe I missed something, but everything should be operating automatically without you turning on a manual switch.
Yes everything works just fine automatically. What I want to do is add manual control to the fan so that I can circulate air through my home without heating. To do this now, I must go in the basement and flip the switch on the furnace. I currently have a Honeywell programmable thermostat that has the ability for this function. I do not have a wire going to the "G" input of the thermostat so I cannot activate the fan remotely. My furnace is not equipped for this function so I was asking how I could retrofit it. The solution was to replace the manual fan control switch with a relay, add a 24VAC transformer and run a new line from the furnace to the thermostat. This should allow my thermostat to use the manual fan control option.
I'm picking the remainder of my parts up tonight and should be installing it all this weekend. I will post pics of the finished product.