Best Thermostats for Heat Pumps (2026): How to Avoid Expensive Aux Heat

You can buy the most efficient heat pump on the market and still get a shocking winter bill. The usual reason is not the heat pump. It is the thermostat telling the system to switch on its backup heater when it does not need to.

This guide explains what a heat pump thermostat has to do, which settings save the most money, and which models handle heat pumps well. We have not lab-tested these thermostats; the picks are based on their published features, installation manuals and long-running owner and installer feedback. Check compatibility with your own system before you buy.

Why heat pumps need a different thermostat

A furnace has one job: make heat. A heat pump moves heat, and it does three different things depending on the weather. It cools in summer, heats in winter by reversing a valve (the O/B wire on your thermostat), and when it cannot keep up on the coldest days it brings in auxiliary heat, usually electric resistance strips or, in a dual-fuel setup, a gas furnace.

That auxiliary stage is where the money goes. Resistance heat turns one unit of electricity into one unit of heat. A heat pump in ordinary winter weather turns that same unit into two to three units. Every hour your system runs on aux instead of the compressor, you pay two to three times as much for the same warmth. A thermostat that is not set up for a heat pump will often call for aux heat far more than needed.

What to look for

Heat pump support with O/B control. Almost every modern thermostat claims this, but check that it supports your exact setup: single or two-stage compressor, and whether your backup is electric strips or a gas furnace (dual fuel).

Auxiliary heat lockout by outdoor temperature. This is the most valuable setting. It stops the system using aux heat above a chosen outdoor temperature, so the efficient compressor does the work. Installers commonly set it around 30–40°F (about −1 to 4°C); owners of cold-climate heat pumps often go lower. Your installer can tell you the balance point of your system.

Smart recovery that does not panic. Big overnight setbacks are a classic aux trap: the house is cold at 6 a.m., the thermostat sees a large gap and fires the strips. A good heat pump thermostat warms up gradually with the compressor, or lets you keep setbacks to a few degrees.

Wiring. Most smart thermostats need a C (common) wire for steady power. If you do not have one, check whether the model includes an adapter before buying.

The picks

Settings that save the most

Whichever model you buy, a few minutes in the installer settings matters more than the brand. Set an aux heat lockout based on your system’s balance point. Keep winter setbacks small, around 2–3°F, or use the thermostat’s smart recovery. Do not use emergency heat as a normal mode; it is meant for when the heat pump itself has failed. And if your thermostat shows aux running often on mild days, ask your installer to check the staging settings.

The cheapest heat in a heat pump home is the heat your compressor makes instead of your backup strips.

Do smart thermostats really save money?

Yes, but modestly, and mostly through scheduling. ENERGY STAR puts the average saving for a certified smart thermostat at about 8% of heating and cooling energy. For heat pump homes the bigger win is avoiding unnecessary aux heat, which depends heavily on how badly the old thermostat was configured. If you are still deciding whether a heat pump makes sense at all, start with our honest numbers on heat pumps.