Three of the most common problems with Comfortmaker gas furnaces are a lack of heat, blowers that run continously and noisy operation. The specific problems with Comfortmaker gas furnaces depend on the particular model.
A lack of heat from a gas furnace is caused by a faulty thermostat, closed valve or blown fuse. Homeowners can troubleshoot the problem by checking that the thermostat is in heat mode and on the correct temperature setting. Faulty thermostats and blown fuses need to be replaced. The appliance should be checked for closed valves, which must be opened to get heat.
A blower that runs continuously indicates a faulty fan or incorrect thermostat settings. Homeowners can fix the problem by checking to see if the thermostat is on a "continuous" setting and then adjusting the thermostat to the correct setting as indicated in the appliance’s user manual. Faulty fans need to be replaced.
Finally, noisy furnace operations indicate incorrect pilot light settings, a dirty gas burner or a faulty motor, depending on the specific noise. A rumbling noise requires homeowners to use the correct settings for the pilot light and clean or replace the burners as described in the user’s manual. Homeowners can resolve a high-pitched noise by lubricating the blower motor ports.