- Phase control failure with Part #12055902MF (metal face) - The phase controller limits the voltage to the combustion fan. On high heat, the fan should have line voltage around 120 volts, AC. As you decrease the heat setting, the voltage should fall proportionately. Heat setting 1 has the least amount of voltage and the fan will spin slowly. As we increase the heat setting, the voltage increases. If the voltage dips or spikes as you move the heat setting up or down OR if the voltage does not change, the controller needs to be replaced or the phase control in the board needs to be replaced.
- Modified Electrical Waveform (All blackface plastic controllers) - Electrical motors require a pure sine wave (a sinusoidal waveform) to be sent from the controller. If the controller is modifying the waveform (the controller was damaged due to a power surge), the power being sent to either blower will cause the motor housing to become extremely hot to the touch. When the motor itself gets over 140°F the motor will shut down (thermally protected) to prevent the motor from starting a fire. Once the motor cools, it will restart but usually, by then, the fire in the stove will be out or the stove will have shut down due to an error. Does your stove shut down occasionally for no reason? Is there a pile of half burned pellets in the firebox? A thermal shutdown of the combustion fan is usually the culprit. The solution is replacing the controller. If the blower still gets hot or vibrates after the controller is replaced, replace the blower too, for good measure. Control board failures that affect other components can do permanent damage to the component.
NOTE: If the TSTAT jumper wire is missing, and you do not have a thermostat installed, your stove will operate on Heat Output position # 1 all the time and at all settings and BOTH the heat range and blower range lights will flash on and off.