We had a Lennox XP19 HP installed. We love it so far & has been doing a great job on keeping us cool... but how can I tell what stage it is running in? This was a question I was going to ask the installer, but unfortunately I was out of town when it was installed.
So far, it seems to always sound about the same whether it is an 80deg day, or a 100deg day - very quiet! Not sure if it has just been running in 1st stage all this time - or if it has been running only in the 2nd stage so far.
We have the Lennox Elite (Honeywell VisionPro) 3-Heat/2-Cool digital touch screen Thermostat.