I just had two 2.5 ton Weather King heat pumps and air handlers with electrical heat strips installed in my two story home. The thermostat installed has four options...Off, Cool, Heat, and Emergency Heat. I understand when the outside temp. dips low enough, the outside coil will freeze up and reverse to cool mode to pump heat outside to thaw the coil. The heat strips are then used so the home will still be slightly heated instead of cooled. I also know the heat strips are designed to be supplemental to the heat pumps when the temp. is low enough that the heat pumps can't heat enough on their own. I also know the strips are expensive to run.
My installation contractor told me that I always needed to set my thermostat to emergency heat if the temp. was going to drop below 40 degrees I believe. From what I've read, emergency heat only uses heat strips but auxiliary heat uses both the heat pump and strips at the same time. So does that mean since I don't have an auxiliary setting on my thermostat that my system will not work in auxiliary mode and only heat strips are being burned all night in emergency mode?? Or is the regular "heat" setting actually auxiliary and only uses the strips when needed?
I didn't realize it was going to drop below 40 last night so I woke up some time with my outside unit(s) cutting on for a short time then shutting off so I assume they were freezing up. I then quickly switch both thermostats to emergency heat. The heat pumps wouldn't have been damaged, would they? Is it not smart enough to know it's freezing up and turn the heat strips on?
I've never known of a system where I've had to be so constantly aware of the outside temperature and switch the emergency heat on and off, though most of my other systems have been all gas or gas piggyback.
Other than keeping both floors the same temp, installing a programmable thermostat and/or an outdoor thermostat in the heat pump to keep the heat strips from coming on above a certain temperature, are there any other options? Are those expensive options?
I live in central Alabama if that helps.