[prottog]

> Also, they are designed to run constantly in order to maintain the set temperature

Not all heat pumps are variable-speed like you describe. My own home, built in 2000, has a single-speed heat pump that kicks on 100% or off, like a regular old AC unit.

[fullstop]

Right, what I'm trying to say is that it is normal for it to be on 100% of the time when it is cold out. If you are used to gas heat which can turn on for 15 minutes, overshoot the set point, and then be off for the next 45 minutes, a heat pump will seem strange.

Mine is a variable speed unit, but that's not the function that I'm talking about.