Hello group,
I have a honeywell wifi thermostat RTH8580WF and a Luxaire gas furnace LP9C080B12MP12CA. As of right now it only has a 4 wire system from the T-stat to the furnace and it really should have a 5 wire. I want to do the 5 wire so I can turn on the blower motor without the need to have the furnace or AC on.

So my general question is when I add the 5 wire between the tstat and furnace which letter would I need to hook up to to allow the blower to run independent of the furnace or AC?

I've been searching on youtube and other places online but not found a good answer.

Thanks for any help
Joel

 

Usually the G terminal controls the fan relay.

 

Thanks Paul,
As of now there is no wire hooked to the G terminal on the tstat but there is a jumper on the furnace going from G to Y/Y2. when I get the wire run would you assume the jumper would be removed as I would think the jumper is to supply power to the blower when the system is calling for heat or AC?

 

You are correct.

When you run your new wire/cable..... connect the G from the stat to G on the control board and remove the Y to G jumper.

 

Thanks for the confirmation PJ. You guys saved me $100 service charge. To run and install the wire. 😂