Help needed, install programmable t-stat

[jdknight]

Church has lennox ES 5Q5 941 1P furnace, heat only. Bought LUX brand CAG1500 series t-stat to install so we can program. Do not know how many transformers heating unit has. Do not know which wires to hook up, diagram is confusing. Don't know what to do with green wire, afraid I will blow either transformer or new t-stat. Help!

[Jay11J]

Ok, I saw your pvt msg to me before I saw this.

I am going to post of what I sent back to you on the pvt. msg.

Hello Jay,

Originally Posted by jdknight
we do not know if the unit has one or two transformers. The furnace is old, lennox ES5Q5-941-1P

Yes, it's an oldie! 1980 give/take a couple of years.
It's a single transformer, and you will need to leave the jumper between Rh/Rc

The green wire is in question.

the green will go to the G. That is your fan switch, when you turn the fan ON, the fan itself will come on to help move air around, be good to use if day you need air movement in the church.

So you should have, Rh/Rc, W, G wired up.