Changing to 'e heat' on your heat pump thermostat will increase your electric bill
Every winter we talk to customers with heat pumps who switch their settings to "e heat," "EM heat" or "auxiliary heat" at the first sign of frost. If you want to take advantage of the energy-efficiency of a heat pump, making that switch may be a bad idea.
A heat pump draws heat from outside air. When temperatures drop, a heat pump draws less heat inside. Eventually it can't provide all the heat needed and supplemental heat from your furnace kicks in.
That furnace heat -- called electric resistance -- is 100 percent efficient. But heat pump heat is 200 to 300 percent efficient. If you switch your thermostat to the e-heat setting you're shutting off the heat pump and relying entirely on the furnace. Which means you're surrendering potential energy savings.
As energy expert Dr. Allison Bailes states, if you want to save on your electric bill, keep the thermostat at the "Heat" setting. Save the emergency setting for a real emergency, such as when your faithful old heat pump quits working.
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