PDA

View Full Version : Trouble shooting malfunctioning central air unit


davidme
Jun 20, 2007, 03:47 PM
Our home utilizes 2 A/C central air units.
Downstairs is operationg OK. (Handler and compressor)

Upstairs unit (handler) is blowing, no condensation on "shut off valve".
No "icing" on coils.
COMPRESSOR fan blades did require a "jump start" (I used a stick to start blades turning).
However, at this time, air is coming through vents very warm air only. (Thermostat at control panel indicates 83degrees).

Can someone walk me through some troubleshooting steps? (A/C people coming tomorrow afternoon, but house is very hot tonight!)

Thank you.

Stratmando
Jun 20, 2007, 04:03 PM
Since your Compressor Fan could "Jump Start", Tells fan or fan capacitor has a problem.
Also tells contactor is working.
The odds of Fan Motor, and Compressor going out at the same time, strange, unless
Problem with Good voltage making it to unit, Common Items for the 2, are wire, the
Breaker and the Contactor contacts.
24 volts making it from thermostat, or you couldn't jump start.

Stratmando
Jun 20, 2007, 07:29 PM
Hoped it helped , you always have downstairs. Thanks

davidme
Jun 21, 2007, 05:57 AM
Thank you, Stratmando.
The tips were great. Fortunately, our A/C service is coming this morning!
I noticed that the pipes leading into house were not cool/cold. Also, reached into the unit and the motor that ran the fan blades was extremely HOT as opposed to the one on the other unit: COLD and "sweating" (water).

So, just more info. To give repair service tech today!

Thanks again for your help.

Stratmando
Jun 21, 2007, 06:01 AM
Let me know what they find, curious, Good Luck.

davidme
Jun 21, 2007, 06:09 AM
Will do.
This is a great "help line" and I plan to tell others about it and use it again.

Thank you.

davidme
Jun 21, 2007, 05:57 PM
Stratmando,
Tech came. Says he replaced something called "dual capacitor 5+5".
I don't know what this part looks like. ($140+service charge/$65)
Can you tell me what to look for and what (new) part may look like?

Thanks.

Stratmando
Jun 21, 2007, 06:36 PM
You would have to remove cover where wiring goes into from Disconnect, Usually has contactor and capacitor. I would say a 5+5, is 2 capacitors in 1 Oval shaped aluminum can with 3 push on terminals, 1 terminal common to both, then 5 Mfd off each other 2
Terminals.