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Honeywell Home T4 Pro Thermostat User Manual


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Troubleshooting

If you have difficulty with your thermostat, please try the following suggestions. Most problems can be corrected quickly and easily.

Display is blank

  • Check the circuit breaker and reset if necessary.
  • Make sure the power switch for heating & cooling system is on.
  • Make sure furnace door is closed securely.
  • Make sure fresh AA alkaline batteries are correctly installed.

Heating or cooling system does not respond

  • Press Mode button to set system Heat.  Make sure the desired temperature is set higher than the inside temperature.
  • Press Mode button to set system Cool . Make sure the desired temperature is set lower than the inside temperature.
  • Check circuit breaker and reset if necessary.
  • Make sure power switch for heating & cooling system is on.
  • Make sure furnace door is closed securely.
  • Wait 5 minutes for the system to respond.

Temperature settings do not change

  • If display says “unlock”; see page 5. If not, verify you are in the correct mode (heat, cool, em heat or auto).
  • If you are in the correct mode, but you cannot set the heat from 40 °F to 90 °F (4.5 °C to 32 °C), or set the cool from 50 °F to 99 °F (10 °C to 37 °C), you may have range-stops restricting your setting. Check with the installer to see if they set range-stops.

“Cool On” or “Heat On” is flashing

  • Compressor protection feature is engaged. Wait 5 minutes for the system to restart safely, without damage to the compressor.

Electrical Ratings

Electrical ratings table

5-year limited warranty

For warranty information go to Honeywellhome.com/support


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