Some furnace problems result from simple issues that anyone can fix. Doing so eliminates having a heat repair company visit your home. Diagnosing and fixing other issues takes more expertise.
It is also worth pointing out that furnaces have blinking red or green lights that provide error codes. Check for and write down or use your phone to record the error codes, which display as a series of short or long blinks. So, here are common furnace problems and how to diagnose them.
Problem #1 is a dirty flame sensor from soot accumulating on the sensor. The flame ignites for a few seconds and goes out, but scrubbing the sensor will fix the problem.
Problem #2 is a dirty furnace filter. A dirty filter keeps the furnace from drawing the correct air volume. The furnace works but may heat the house but falls short of the thermostat setting.
Problem #3 is a bad inducer motor. The primary symptom is a very hot inducer motor that needs replacing.
Problem #4 is a bad blower motor, often accompanied by the smell of burnt plastic. It also needs replacing. Finally, problem #5 is a bad control board. It is more difficult to check since you need an electrical meter to determine whether the board is receiving and sending power.
