Ecobee Not Heating or Cooling: What to Check First

By Ray Bennett · Updated 2 October 2026 · 6 min read · Checked against the maker’s manual

Ecobee Not Heating or Cooling: What to Check First

Short answer

Start with ecobee's Test Mode. If two minutes of heat or cool brings air from the vents, the fault is a setting: the system mode, the differential, or the 35°F Compressor Min Outdoor Temperature on a heat pump. If nothing comes, it is a loose wire, the wrong configuration or the equipment itself, and a screen that keeps rebooting points at a full condensate pan.

When an ecobee asks for heat, the flame icon turns orange, or an orange line runs round the edge of the screen, depending on the model. For cooling, the snowflake turns blue, or the line does. If the house is cold or warm and you do not see that, the thermostat is not asking, and the fix is usually a setting.

Everything on this page comes from ecobee’s own support pages for heating and cooling problems and for its alerts. ecobee splits the problem three ways: the thermostat is not asking, it is asking but nothing comes out, or the equipment runs and the house still will not change.

Before you start

What to carry: your phone for a photo of the wires, and a torch. Fifteen minutes.

Gas or electric? Both. ecobee’s steps cover gas and electric furnaces, air conditioners and heat pumps, with or without auxiliary heat.

Take the photo first. ecobee’s steps compare the wires behind the thermostat with the wiring the thermostat thinks it has, and ecobee support asks for photos too.

Know what powers it. ecobee notes the thermostat is powered by the furnace or air handler, so when the equipment loses power, the ecobee goes dark with it.

Two safety points from ecobee. Breaker off before the drain pan. For a cooling system that stops, ecobee says to turn off the main power to the equipment at the breaker before looking at the float switch, the drain pan and the drain line.

A furnace that overheats shuts itself down. ecobee says a furnace’s safety equipment turns the heating off when it overheats, and the blower may keep running to cool it. Find out why rather than resetting it again and again.

Test Mode: the first two minutes

ecobee's first step is Test Mode. Air from the vents means a setting is stopping the call; no air means wiring or equipment.

Check 1Free, five minutes

Run Test Mode

Furnace. In Test Mode, turn Heat Stage 1 on for two minutes. Check the vents for airflow and that the air is warm.

Heat pump. Turn Heat Pump Heat Stage 1 on for two minutes, confirm the outdoor unit runs and the air is warm. If you have auxiliary heat, test Aux Stage 1 the same way.

Cooling. Turn Cool Stage 1, or Heat Pump Cool Stage 1, on for two minutes. The outdoor unit should run and the air should be cool.

What it tells you. Warm or cool air means the equipment works and a setting is stopping the thermostat asking. No air, or the equipment not running, means the wiring, the configuration or the equipment.

It works in Test Mode: the settings

Three settings stop an ecobee asking for heat or cooling even when the equipment works.

Check 2Free, five minutes

Check the three settings

The system mode. It must be Heat, Cool or Auto. ecobee says that in Cool you see a snowflake, and in Auto half a snowflake and half a flame.

The differential. The room must be past the set temperature by a margin before the ecobee asks, about 0.6 to 1°F by default. ecobee says Away, or a comfort setting marked as usually away, adds another degree to save energy.

Compressor Min Outdoor Temperature. Below this outdoor temperature, 35°F by default, ecobee will not ask the compressor to run. On a heat pump without auxiliary heat, that means no heat. It lives under Settings, Installation Settings, Thresholds.

Free Cooling. On a system with a fresh air ventilator, ecobee may cool with outside air instead of the air conditioner. It can be turned off under System, Ventilator.

It asks, but nothing comes out

Check 3Free, ten minutes

Check the wires and the configuration

The wires. Pull the ecobee gently off the wall and tug each wire. ecobee says to pay special attention to Y1, or the PEK terminal if you use the Power Extender Kit. Reseat a loose one by pressing the tab, sliding it out and back in.

The configuration. Go to Settings, Installation Settings, Equipment, then Wiring. The highlighted wires must match your photo. If they do not, choose Reconfigure Equipment and follow the menus: what each thermostat wire does.

Then test again. ecobee says to use Test Mode again after fixing a wire or the configuration.

It runs, but the house will not change

Check 4

Look at the equipment

Furnace power and codes. Check the furnace breaker. ecobee also says many furnaces show lights or codes when they have a problem, and your furnace manual explains them: why a furnace will not come on.

An overheating furnace. ecobee names reduced airflow first: change or clean a clogged filter and make sure the air intake is not blocked. It also names dirt and carbon build-up, a job for a technician.

A heat pump in the cold. ecobee says heat pumps struggle below the maker’s balance point, and to set the compressor threshold back to the default or the maker’s figure if it was lowered: why a heat pump stops keeping up.

An ecobee that keeps rebooting in summer. ecobee lists this with water around the air handler and a full drain pan. A float switch cuts the power when the pan fills. Breaker off, empty the pan and clear the line: how to clear a clogged drain line.

Cooling runs, the air is not cool. ecobee says extreme outdoor heat or an equipment problem can cause it, and to watch it over a longer time and call a technician if it continues.

The alerts ecobee can send

Check 5Free, five minutes

Set the alerts that warn you early

Low Temp and High Temp. ecobee alerts you if the house falls below or rises above a level you set, to prevent freezing or heat damage.

Aux Heat Runtime. On a heat pump, an alert if the auxiliary heat runs longer than a set time in 24 hours, 3 hours by default. It can be an early sign the heat pump is not carrying the load.

Aux Outdoor Temp. An alert if the auxiliary heat is called for when it is warmer outside than a temperature you set.

Heating and Cooling Alerts. Leave these on. ecobee says turning them off stops the alerts that tell you the system failed to heat or cool.

Questions people ask

Why is my ecobee not heating?

Run Test Mode first. If heat comes, check the system mode, the heat differential and, on a heat pump without auxiliary heat, the Compressor Min Outdoor Temperature. If nothing comes, check the wires and the configuration, then the furnace.

Why is my ecobee not cooling?

Same order: Test Mode, then the mode, the cool differential, the compressor threshold and Free Cooling. If the ecobee keeps rebooting, look for a full drain pan tripping the float switch.

What is Compressor Min Outdoor Temperature?

The outdoor temperature below which ecobee will not ask the compressor to run, 35°F by default. It is under Settings, Installation Settings, Thresholds.

Why does my ecobee keep turning off and restarting?

It runs on power from the furnace or air handler. ecobee lists a full condensate pan, where a float switch cuts the power, and on electric furnaces an overheat shutdown.

What does the orange line on my ecobee mean?

It is asking for heat. A blue line, or a blue snowflake, means it is asking for cooling.

What is the Aux Heat Runtime alert?

An alert that the auxiliary heat has run longer than a set time in 24 hours, 3 hours by default. On a heat pump it can mean the heat pump itself is not keeping up.

Sources: ecobee support: "Troubleshooting Furnace Heating Issues", "Troubleshooting Cooling Issues" and "How to set Reminders and Alerts on your ecobee thermostat"