Intermittent problem with blower start


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Old 06-30-12, 03:46 PM
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Intermittent problem with blower start

I have a 14 yr old Goodman heat pump. During A/C season only (works okay on heat) the blower occasionally fails to start. I had the blower motor and capacitor replaced a year ago. This problem existed before that.

The outside unit runs as it should, but the blower doesn't engage. Flipping the switch at the thermostat off and back on fixes it.

Is there a relay or high temp switch in the air handler that may be causing this? I don't mind swapping out a part or two, but I'm not an electrician.

Somebody out there has surely seen this problem, right?

Thanks for any help.
 
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Old 06-30-12, 04:39 PM
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I would start with your thermostat. If you would like to verify the problem you will need a voltmeter and know how to use it.
 
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Old 06-30-12, 07:58 PM
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Yeah, I have a voltmeter and basic knowledge on using it. I used to own several restaurants and repaired my own pizza ovens and warming racks. Didn't touch refrigeration or HVAC. I'm okay with electrical, but not a pro.

Again, this is an intermittent problem. Sometimes 2 or 3 times a day sometimes weeks between occurrences.

Thanks for the reply.
 
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Old 06-30-12, 08:12 PM
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While the blower should be running but is not you need to check voltage between G and C in the air handler.
 
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Old 06-30-12, 08:26 PM
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G and C? Not sure what that is. What am I looking for? What readings might I get and what will they tell me?

Thanks again.
 
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Old 06-30-12, 08:35 PM
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low voltage terminal board
you are looking for 24VAC nominal
if you have 24V and the blower is inop you need to verify Voltage to the motor.
If 0V then you have a flaky t-stat or a wiring problem.
 
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Old 07-01-12, 01:18 PM
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Checked for power in tstat, across G & C. 25V. Same reading on those wires in the air handler. Didn't see a control board as such. Just a transformer and 4 relays.

No power at the start capacitor. No power across common (Purple) and Hi (Black). I puled the power disconnect on the outside of the unit, then replaced it. Everything started as it should. I now have 245V across purple and black.

With Power at G & C, and no power to the motor, does that mean tstat? Or a bad relay?

Thanks again for the help.
 
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Old 07-01-12, 01:29 PM
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Check the blower relay. If it's part number B13707-?? (might be on underside of mounting plate), replace it.
 
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Old 07-09-12, 10:03 PM
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It was indeed the B13707 time delay relay. I replaced it and haven't had a problem since.

Thanks again for the help.

Scott Worthington
 
 

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