I have a Lennox central air/heat unit, Curious about fan speeds and changing them?

I am a very capable person( so dont give me the %26quot;call a experienced hvac tech%26quot; answers here.) I have a few squirrel cage fans for when I paint and do drywall, and understand that different windings connected to the different wires and hooking them up accordingly will change the speeds. Doing so on one that is just hooked up to a power cord is simple to see and understand, BUT, in my Lennox, all the wires are connected to control(looks like a relay) except a blue one, and I know the black is the high speed.



HOW do I make sure it is set to run on the High speed, as Im not sure of the routing and what takes place in this control.

Also I have read that some?most? unit will manipulate the speeds themselves without intervention. I am certain mine only runs at one speed, and it is currently not enough air volume to majke it to the upstairs(second floor) vents.

And i have tried to regulate the 1st floor vents by closing them slightly and it doesnt work.

Need more air!I have a Lennox central air/heat unit, Curious about fan speeds and changing them?
e/m me at pete0518jr@optonline.net and I'll fill you in!

Very easy to tell you how!I have a Lennox central air/heat unit, Curious about fan speeds and changing them?
You should have someone %26quot;balance%26quot; your system. Turning the fan speed up higher does no good if the plenum cannot handle the load and is not adjusted properly.I have a Lennox central air/heat unit, Curious about fan speeds and changing them?
Try installing booster fans in the ductwork that feeds the upstairs....wire them to turn on with the furnace blower. Check all duct joints if possible for air loss/gaps and tape them with aluminum tape. Check with a Lennox dealer with serial and model numbers to see if your unit is a variable speed or not.