If your programmable thermostat is trying to turn on your home's electric heater, but the blower motor just will not come on, then the electrical start capacitor has likely failed. The good news is that you can easily replace the start capacitor with an insulated screwdriver and about a half-hour's time.
Follow these steps to replace the faulty capacitor in your home's electric furnace:
Turn Off the Power to the HVAC System
Since your heater has a hard-wired connection into your home's power panel, you must turn off the power for your safety. After you turn off the breakers, test the HVAC system with a current tester to ensure it has no power.
Locate the Starter Capacitor
When you remove the cover on the furnace, you will see a cylindrical part that is a couple inches long and has two electrical wires attached to terminals on its top surface. This part is the capacitor you will be replacing.
Remove the Old Capacitor
Using an insulated screwdriver, remove the electrical wires from the faulty capacitor. While removing the part, hold it only on the end that is away from the wire-connection terminals to avoid getting an electrical shock from it.
Discharge the Charge Stored in the Capacitor
As soon as you remove the capacitor, hold the insulated handle of the screwdriver and touch the metal part across both of its terminals. This action creates a complete circuit and will discharge any power stored in the capacitor.
Install the New Capacitor
To install the new capacitor, attach the electrical wires to its top and tighten the screws using your screwdriver. The terminals are both the same and the wires can be connected to either terminal. However, you need one wire on each terminal, not both wires connected to the same one.
Turn the Power Back On to the HVAC System
Turn the power back on at the power panel to restore the electrical current to the HVAC system. If your system has a red "reset" button on the heater portion, then you should press that as well. This will recycle the unit and turn it back on after the power disruption.
Test the Heater to Ensure it Works
Finally, turn the furnace on and verify that the blower motor's function has been restored. For more information, or if you would like professional assistance, contact High Tech Heating Ventilation And Air Conditioning or a similar company.