How to Adjust blower fan speed on a Lennox G40UH(X) Series furnance?

Question

How to Adjust blower fan speed on a Lennox G40UH(X) Series....anyone? I know it can be done as a neighbor told me his repair guy adjusted his up a bit, but did not know how, or what he did.....

Answer 1

Sometimes the belt that drives the fan has an adjustable pulley on it and by tightening it ( making it smaller will cause the fan to go faster.

Answer 2

black wire is high

blue is med high

red is lowest

most of the time, highest fan speed is already being used.

trace the black wire back to the fan control. it should be on a spade bit marked cool or something that distinguishes it from the others.just as long as its not on one marked  -park--  or  L 1 or 2.  those are just dead spaces for wires not being used so they dont flop around.

Answer 3

Most blower fan motors have multiple power ins on them that range in different color wiring, usually about 4-6, each color is a fan speed.