Heat on.
Home still cold?

Look at the thermostat and note the room temperature, the requested temperature, and the mode shown on the screen. Then describe what happens in the rooms. That gives the follow-up conversation a clear starting point.

No response when heat is requested

Tell us whether the display is lit and whether you hear the equipment start. Include when heating last worked.

The system runs, but rooms stay cold

Note whether the room temperature is rising, falling, or staying the same. Say if all rooms are affected.

Some rooms warm up and others don’t

Identify the rooms or floors involved. If you have more than one thermostat, tell us which area each one controls, if you know.

A message appears on the thermostat

Copy the exact words or code into your request. Don’t guess at the meaning or clear the message just to describe it.

On a heat-pump system, “AUX” usually indicates that supplemental heat is operating. The display alone does not tell you which repair, if any, is needed. Include the message and whether your home is reaching the selected temperature.

For a basic check, verify that the thermostat is set to Heat and that the requested temperature is above the room temperature. Follow your equipment’s operating instructions and leave equipment adjustments or electrical work to service personnel.

Manufacturer references: Carrier’s heating troubleshooting guide and auxiliary heat explanation.

You can submit a request without knowing whether your home uses a heat pump or another heating system. If the brand or model is already available in a manual or your records, include it. There is no need to remove covers or access hard-to-reach equipment.

Include your town, when the problem began, whether cooling still works if you already know, and when someone can be reached by phone. For a rental, identify the person who can authorize a visit. That is especially useful when the person reporting the problem is not the property owner.