Do Geothermal Heat Pumps need to be set at a constant temp?
We recently moved into a house with a geothermal heat pump. It has a programmable digital thermostat, so we decided to set it to stay at 70 while we're home, 67 while we sleep, and 60 while we're at work. We've noticed, however, that every time it goes to heat back up - the Auxiliary Heat kicks in. I called the heating guy, and he told me that Geothermal Systems should never be set to change by more than a single degree. So, according to him, we should never set our thermostat lower than 69 or higher than 71 if we usually keep it at 70 - because he says the system will be less efficient if we do.
So - is that right? Is it really more efficient to leave our thermostat at 69 instead of 60 all day on a Geothermal system? I can't seem to find a conclusive answer.
- Brian ALv 71 decade agoFavorite Answer
This is pretty much true. Most programmable thermostats (or thermostats in general) assume that you want the temperature changed NOW and use the backup heat if you change it by more than a couple of degrees to get to the new setpoint as quick as possible. There may be a way to change it so that it does not request backup heat.