[altazink]

I used to have a covensional 2 wire mercury thermostat and have recently upgraded to a digital thermostat that supports more options including being able to turn the fan on automatically.

I want to be able to turn just the fan on and not the whole furnace so I can get better air circulation in my home without heating it more.

Now I have an old standing pilot system that had the old pull button on the furnace that has been removed before I moved in on the box inside the furnace panel.

I want to be able to turn it on from the thermostat itself now

I know I may have to wire an additional wire down the wall which isn't a problem but it's a 24 volt thermostat and I want it turn on the 120 v fan so I can't exacly connect that wire directly into the end that is past the relay. Looked at the fan on/off relay that turns on the fan when the plenum gets hot and turns it off when it gets cooler... is there a way to wire it into that as from what I can tell it's the only thing controlling the fan at this point so I would need to get it to activate it

Thanks

[hvac1000]

Add G wire for thermostat control of blower. Wire new G wire to a new blower relay that will activate with 24 volt control and the relay will jump the old fan control for blower only operation. If you do not know what you are doing contact a local HVAC person that does.