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Phil, Mechanical Engineer
Category: HVAC
Satisfied Customers: 6022
Experience:  Retired HVAC/ Electrical & Boiler contractor. Industrial
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Installed a replacement board lennox was swicthing from cool

Customer Question

installed a replacement board for a68j8401 lennox was swicthing from cool to heat with old board now compressor not kickin on just blows air
Submitted: 1 year ago.
Category: HVAC
Expert:  Phil replied 1 year ago.

Hello, send me a photo of the wiring diagram glued inside the blower service cabinet, and a photo of the thermostat wire connections so I can see the terminal letters and I will mark those up with trouble shooting instructions.

Photo of the diagram needs to be taken close up, in very good light, and exceedingly well focused.

Use the paper clip icon at the right end of your tool bar or the attach files link to the left of your send button to get those to me.

We can go from there,

Customer: replied 1 year ago.
Here they are
Expert:  Phil replied 1 year ago.

Hello again, Lennox controls can be a bit less standard than most other systems, in this case you have a thermostat that does not match the system. and it is wired for a conventional AC system (not a heat pump) and your lennox unit is a heat pump.

This is not something 99% of home owners could sort out no matter how extensive the coaching, it is something that most HVAC contractors would avoid or have a hard time with... but a Lennox dealer might feel obligated to fix it up for you... my estimate on his price is in the $400 to $800 range

Expert:  Phil replied 1 year ago.

Let me know if you want help in locating a qualified Lennox dealer or not, if you do tell me which direction you are from the center of the nearest city and will take a look for you.

Expert:  Phil replied 1 year ago.

Meantime I will opt out, hopefully some courageous soul here will tackle this one for you.

Customer: replied 1 year ago.
No that is not it.It has something to do with the new board being wired slightly different
Expert:  airheatman replied 1 year ago.

1.When you say replaced board are you referring to a control board inside of the air handler or the thermostat?

2. Wiring in picture on thermostat does not appear correct.Has this wiring been changed

3.Is this a new thermostat?