Capacitors are a key component to your furnace’s overall performance and just like most parts, will eventually wear out. Here are some indications of a weak or faulty capacitor:
1. Noisy! – If your furnace’s motor is running a lot louder than normal this is a sign that you might need a new capacitor. Also, a worn-out capacitor will make a clicking sound as the furnace starts up.
2. Burning Odor – An old or malfunctioning capacitor will cause the motor to overheat and may even cause the wires to melt, hence the burning odor.
3. Will Not Start – A furnace with a bad capacitor will not start, but before that happens you may notice that it won’t run at full power or will run sporadically. This is a good indication that the capacitor needs to be replaced.
4. Visual Signs – A faulty capacitor can become swollen with bulging ends. In some cases a capacitor may even swell so much that the ends blow open and begin leaking oil.
5. Rising Gas/Electric Bills – A weak capacitor causes the motor to run less efficiently and your bills to go up.