You’ve seen the “Emergency Heat” or “Em Heat” setting on your heat pump’s thermostat for awhile now. But you have no idea what it means or when to use it.
Some people think they should use it when it’s really cold outside (nope).
So when SHOULD you use it?
In short, you should only use it when your heat pump isn’t working properly.
To know why, you need to understand what the Emergency Heat setting does. And to do that, you need to know how a heat pump works—especially in freezing weather.
Heat pumps are like “heat transporters”; they can push heat from inside your home to the outside (in summer) and pull heat in from the outside to the inside (in winter).
Ah, but there’s a problem. When it below 40 degrees outside, a heat pump can’t properly heat your home. So it needs a supplementary (auxiliary) heat source to keep you warm.
Heat pumps come with a built in auxiliary heat strip (like the ones found in your toaster). But it’s an energy guzzler and runs up your electric bill like crazy.
So in colder climates, heat pumps are usually paired with a gas furnace for secondary heat. This is called a dual fuel/hybrid heat system.
Now we can move on to...
The Emergency Heat setting locks out the heat pump and forces the auxiliary heat source (in Minneapolis homes, it’s most likely a gas furnace) to provide 100% of the home’s heating.
You’d only use this setting when the heat pump malfunctions or is damaged and fails to provide heat. Emergency Heat allows your backup heater (gas furnace) to keep you warm until a heating & cooling technician can solve the problem.
Minneapolis Saint Paul Plumbing, Heating and Air is the plumbing and HVAC contractor Twin Cities area residents count on. We have been serving the area since 1918.