Thermostat

Thermostat
A new thermostat should be installed only after these tests and checks have been carried out:
^ Pinpoint Test A, B or C
^ Thermostat Visual Inspection Thermostat Visual Inspection

1. Remove the thermostat.
2. Examine the thermostat for signs of damage including:
^ Valve not fully seated (light visible through the valve)
^ Foreign material lodged in the main valve
^ Bent or broken frame or flange
^ Bent or broken spring
^ Bent or broken valve or valve stem
^ Wax leaking from wax reservoir or a bulge in the reservoir
^ Any other damage or distortion

3. NOTE: If no damage is found during the inspection, do not attempt to open the thermostat using hot water or other heat sources. This method is not an accurate means to test the function of the thermostat and may damage the thermostat.

If damage is found during the inspection, remove any foreign material or broken pieces and install a new thermostat.
4. If no damage is found during the inspection, continue troubleshooting the system concern. Go to the Symptom Chart for further instructions. Symptom Related Diagnostic Procedures