I am replacing Thermostats for Lennox Model #HP18-211U-2P. This number was on top of the Unit

Does this unit require a thermost with auxillary heat connection?

There is another number: CB18-21-1D, I think that's from the outside part.

Sorry to be so lost. I could not find this model mentioned on the Lennox site so couldn't look at product manuals.

 

That HP I d say stands for a heatpump. So make sure you get a heatpump tstat. Besure and mark all wires and also turn the power off before you start on the tstat.

 

Thanks Ed
I did find the manual finally
but the HP thermostats all say - 'not for two-stage' or 'for two stage heat' pumps and then they also have some that have no indicator for auxillary heat, which is what I thought all heatpumps have.

I paid to have all the ducts cleaned and equipment cleaned and tested, but the units weren't wired correctly the tech said. So I paid them to rewire it so I could color match the wires to an off-the-shelf thermostat.

Now I can't figure out which type to buy....

I tried calling Lennox tech support- and was on hold for 20 minutes and then gave up.