AboutJ Cook Expertise With 25+ years experience, I am familiar with residential, commercial, and industrial HVAC equipment including but not limited to boilers, chillers, reciprocating and screw compressors. I am trained in all manners of control wiring.
Experience I currently have three HVAC licenses and Refrigeration license by the State of North Carolina. I have been in this field for over twenty years. I have been a service technician for a contractor and also worked at a state college in the repair and maintenance of steam lines and equipment. I am currently the Building Maintenance Superintendent for a municipality.
Question My 4 year old furnace (Ultra Max III, Propane) refuses to start. I can initiate the blower suing the door switch, however there is no ignition. The furnace is not equipped with a pilot light. Power is available, and I can set the fan to "Run" at the thermostat (Honeywell, mercury switch) at it will run. Set to auto it waits for the furnace to kick in. Not sure if it is the ignition module or the thermostat,
Answer The blower on every furnace is delayed when in the auto mode so the heat exchanger can heat up and not deliver a blast of cold air into the home before the exchanger heats up. If the furnace shuts off before the fan energizes, the fan control is defective or needs to be adjusted to a lower on temperature. Setting the fan switch in the on position overides the fan control. Thanks J
