my hvac is not blowing hot air. The outside heat pump unit runs, but no air inside?
Question by : my hvac is not blowing hot air. The outside heat pump unit runs, but no air inside?
The heat pump unit outside is running but the unit inside is not blowing any air in the house. When I checked the air handler in the attic, the circuit board has all the right lights on etc.. and when I reset it, I could hear a humming sound coming from the box next to the blower, but it was not spinning. I tried manually spinning the blower and it kept spinning and worked for a few hours. Now it is not spinning again. I can still hear the humming sound coming from where all the wires are attached in the box next to the blower but no still no air. I need to fix this myself, any suggestions? Could it be the blower itself, or could it be something else such as a capacitor or starter? Any help would be much appreciated!
Best answer:
Answer by David Clarke
cloggedair filter
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January 27th, 2012 at 2:53 am
Sounds like the capacitor for the blower motor has failed. A capacitor provides a brief burst of high voltage to start an electric motor spinning. When it fails the motor won’t start spinning.
Get the numbers off the side of your capacitor (mounted on the blower housing) if it is an external capacitor and replace it. Turn off the power to the furnace at the circuit breaker before doing this. ALSO GROUND THE CAPACITOR TERMINALS TO METAL WITH A SCREWDRIVER TO DISCHARGE AND VOLTAGE IN THE CAPACITOR.
Now a downside-some blower moters have an INTERNAL capacitor. Then you have to replace the entire moter.
Until you get this corrected. Turn the fan switch on your thermostat from “auto” to “on” and spin the fan by hand like you did before to get it spinning. Your fan will run constantly, but you’ll get heat as the heat kicks on and off.
Good Luck
January 27th, 2012 at 3:31 am
The capacitor has failed. What you can do toll you get the capacitor replaced (which you can do yourself) is set the fan on the thermostat from Auto to ON and leave the blower on all the time till you get the new capacitor. So do the spin trick and you should be back in business.
The capacitor has a rating on it such at 5uf 370V you need to replace it with what ever is on the side of the capacitor. To change it kill the power to the actually air handler and remove one wire at a time. Be cautious not to touch the spade connectors as there is stored power in the old capacitor. Simply install the new capacitor and make sure the wire are on opposite terminals like that of the old one. Its does not matter which wire is on say the left or right so long as the are opposite of each other left and right.
Turn the power back on put the fan back to auto and you should be good to go.
FYI you can get the capacitor at any electrical supply house, grainer local or order one off line.
Leaving the fan on all the time till you get one will ensure that your heating system will work and deliver heat. Make sure the filter has been changed. The heating system will cycle on and off as needed per the thermostat. Just for right now the blower will stay running so you have heat.