We just had a Lennox G60UHV variable speed furnace and a Lennox 13ACX A/C unit installed.
The thermostat they installed was a White Rodgers 1f80-361. It specifically states in the manual that it is for single stage heat pump systems and DO NOT USE WITH multi-stage systems.
Did they install the wrong t-stat or is there something about the furnace that does not require a multi-stage t-stat? Is multi-stage different than variable speed?