Skip navigation

Serving Colorado Springs and the surrounding area


24 Hour Emergency Service


Will My AC Freeze If I Lower the Thermostat Too Far?

ice-on-an-acYou may have heard about an air conditioner’s indoor coil freezing over because someone lowered the thermostat too far. This may sound a bit fanciful: after all, the lowest setting on most thermostats is 60°F, which is definitely far above freezing. 

But there’s truth to this—an air conditioner can suffer from coil-freeze with the thermostat lowered too far. It’s more likely to occur at higher altitudes, such as more than 5,000 feet above sea level. Colorado Springs is 6,035 feet above sea level, so the danger of a frozen coil is extremely real for our ACs. 

Even if your AC doesn’t freeze up because of a low thermostat setting, you still shouldn’t lower the thermostat too far because it creates other problems for an AC leading to air conditioning repair in Monument, CO and high costs to run the system.

Don’t lower the thermostat below 72°F

One of the major pieces of advice you’ll hear about thermostat settings is not to lower the thermostat below 68°F when cooling a house, no matter the heat hourside. Well, the same way we have to adjust baking temperatures at higher altitudes, we also have to adjust thermostat setting recommendations. So this is a special warning that applies to us here in Colorado Springs: don’t set the thermostat lower than 72°F when running the AC.

The higher altitude creates a different situation for an air conditioner so that it’s easier for the evaporator coil to freeze over. At sea level, it’s unlikely for an AC to suffer coil-freeze just because of a low thermostat setting. Up here, going below 72°F on the thermostat puts an air conditioner at a high risk of a freeze-over, and that means the air conditioner will stop cooling the air, period.

We recommend 78°F for the thermostat in hot weather

Honestly, you shouldn’t need to lower the thermostat down to 72°F in the first place. Your air conditioner has a 20° temperature differential, which means it can lower the indoor temperature 20° from the outdoor temperature. So a setting of 78°F is within the AC’s range even if it’s 98°F outside, and that’s a rare condition here. You’ll find that 78°F is comfortable for most people, and it helps save energy for the air conditioner. 

The AC coil can freeze for other reasons

You may keep the thermostat set to coil-safe settings and still experience ice forming along the indoor coil. There are several other causes of the coil freezing, such as leaking refrigerant and a clogged air filter. A clogged air filter is something you can remedy on your own (although you may still wish to call our professionals to handle de-icing the coil). A refrigerant leak is a major problem that must have professional repairs or else the whole AC is in danger of breakdown. Just keep in mind that ice appearing on any part of the air conditioner is not normal and usually a signal the system requires professional service. 

Robbins Heating & Air Conditioning serves Colorado Springs and the Surrounding Areas. Call us for AC service when you need it—we offer 24/7 emergency repairs.

Comments are closed.