HVAC Procedure and Performance Guide

Calibrate thermostat

Training for this procedure can be found in these courses:

                         131 – Oil Heat l  and  161 – Boilers l


Thermostat must be calibrated according to manufacturer’s specifications. Calibrated thermostat must respond to space temperature in which sensing element is located, heat anticipator must function to specifications and thermostat must control air conditioning equipment to provide desired space temperature.  Applicable safety procedures must be followed.


    1. Review manufacturer’s specifications.
    2. Determine type of thermostat, correct test instrument to use and manufacturer’s calibration requirements.
    3. Collect tools, equipment and materials.
    4. Put on safety and protective equipment and apparel.
    5. Position temperature-measuring instrument next to thermostat sensing element.
    6. Connect electrical test equipment according to manufacturer’s instructions.
    7. Place system in operation.
    8. Determine current required by heating coil or heat-control device on furnace or heating unit; adjust thermostat heat anticipator according to manufacturer’s specifications. (Note: This is a critical adjustment and must be made accurately).
    9. Set thermostat for desired space temperature and verify that correct signal is generated & that system responds.
    10. Note space temperature at which thermostat is satisfied at new setting and compare to thermostat setting.
    11. Adjust thermostat pointer to correspond to space temperature noted.
    12. Note space-temperature overshoot or undershoot on heating cycle and recalibrate heat anticipator as required.
    13. Disconnect electrical test devices and remove temperature-measuring instrument.
    14. Leave equipment in required operating status.
    15. Remove safety and protective equipment and apparel.
    16. Gather tools, equipment and leftover materials, and leave work site clean.