0 %

DIY guideThermostat

Check the thermostat's schedule and calibration

Compare its reading with a thermometer, move what throws it off, fix the schedule, and check the thin wires at its base.

  • 20 to 40 min
  • 7 steps
  • Every step animated
Check the thermostat's schedule and calibration: the animation’s first picture

7 steps

Tap a step to watch it again.

  1. Tape a thermometer to the wall beside the thermostat, at the same height. Wait 15 minutes.

  2. They should be within a degree or two. Off by more? Many thermostats let you adjust the reading in their settings.

  3. Sun, a lamp, a draft or a vent blowing on it throws the reading off. Move what you can.

  4. Step through each day's times and settings. Fix any that don't match when you're home, away or asleep.

  5. Set it to Off and pull the front off. The thin wires should sit firm in their terminals: press a loose one back in.

    Thick wires or a high-voltage label behind it? Put it back: that one is an electrician's.

  6. Press the front back on, set it a few degrees past the room, and listen for the heat or cooling to start.

  7. A reading that wanders, a blank screen, or heat that runs on its own: ask Handyman for a heating and cooling tech.

What you need

  • A thermometer
  • Painter's tape
  • The thermostat's manual (or its model, to look it up)

Call a pro if

  • The reading wanders or the screen goes blank
  • The heat or cooling runs on its own
  • There are thick wires or a high-voltage label
  • A wire is broken, not just loose

Handyman says: Still wrong? I'll find an HVAC tech.

Get a pro through HandymanMessage Handyman

Free for every home. Handyman asks a few questions, then books a pro it trusts.

More heating and air guides

See all 51

Icon Rather have
a pro do it?

Get started