You may know that electric motors need more power when they start than they do when they're running. This is true for the motors in your HVAC too. That's why the fan motor in the condenser and the blower motor in the furnace have capacitors. Capacitors store energy, and they provide the extra power the motors need to start up and get running.
When a capacitor goes bad, it can have different effects on your HVAC depending on if you're running the AC or furnace. You'll need to call an HVAC repair company to put in a new capacitor when the old one goes bad. Here are signs your HVAC could have a bad capacitor and how an HVAC repair technician can help.
Signs Your HVAC Could Have A Bad Capacitor
When the capacitor goes bad in your furnace, the blower motor might not start, or it might start and not run at full capacity. This could cause your furnace to get too hot and trigger a safety mechanism that shuts your furnace off. The furnace might short-cycle a few times and then shut down for good until an HVAC repair technician makes repairs and resets the furnace.
A bad capacitor could cause the motor to strain too, and then you could hear odd noises coming from the furnace. If the motor can't turn the blower at all, there won't be any hot air circulating through your home, and your house will get cool. It's also important to remember that your air conditioner uses the same blower as your furnace. So, a bad blower capacitor could affect your HVAC during the winter or summer.
If your AC won't run and blow cool air through your house, the problem might be a bad blower capacitor. The AC also has another capacitor in the condenser that keeps the fan going. If the condenser capacitor goes bad and the fan doesn't turn, the condenser could get too hot. That might keep your home from cooling down, and it could even cause damage to other parts of your AC due to overheating and strain.
How An HVAC Repair Technician Might Help
Diagnosing a bad capacitor is fairly easy. The HVAC repair technician might look at the status codes on the HVAC control board. The technician can verify a capacitor is bad by testing it with a multimeter. An HVAC capacitor is easy to reach and change. These parts usually don't last as long as the rest of your HVAC equipment, so you might need to have a new capacitor put in after you've owned your HVAC for several years.
Changing the capacitor entails discharging the power held in the old capacitor, disconnecting it from the HVAC, and then putting a new one in place. With the new capacitor hooked up and working, your blower or fan should start up right away and turn at the optimal speed. The repair technician might use the opportunity to clean the blower or fan also just to make sure it will spin freely and not put any strain on the new capacitor or motor.