Insight needed on heat pump troubleshooting

Old 09-14-19, 01:44 PM
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Insight needed on heat pump troubleshooting

There is something wrong with my heat pump, I don't know any specifics on it. On Thursday afternoon it started turning on and off. Sometimes it would start to turn on then shut off right away, or it would turn on for maybe 20 seconds and turn off.

Repair guy came and thought it was the thermostat, it wasn't.

The unit outside was still running, he said the fan was running, but the a/c wouldn't kick on. He thought it was the motherboard.

Came back the next morning, Friday, and put in another motherboard. It worked, until this afternoon, Sat, started with the same thing. I couldn't hear a fan but the unit outside was on. Then about an hour later the unit outside had a jingling noise.

So it's not the thermostat, and it's not the motherboard, though it's strange how changing it had it working for a day.

Any insight on what the issue is?

Old 09-14-19, 01:56 PM
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Welcome to the forums.

Sounds like you need a new tech,

There are two distinct sections..... the inside air handler and the outside condenser. Defrost boards rarely fail in the outside condenser. He changed the board and the problem remains.

In order for us to help you we need to know exactly what's happening.
Is the inside blower working ok but the outside condenser is not running ?

A low refrigerant problem will cause the outside unit to work intermittently.
Old 09-14-19, 02:32 PM
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On Thursday when the problem started the outside condenser and the inside air handler were working, but the a/c blower wouldn't come on, or stay on.

The motherboard was changed on Friday, the a/c was working again. After it was working for about an hour he charged the refrigerant, he said it was low. I asked him if there was a leak and if that was the issue, he said no, it was the motherboard.

Today the the outside condenser is working, though today it was making noise, like it was jingling. I could not hear if the inside air handler was running.

My thermostat is a Honeywell ProSeries, at the moment I have it on autofan and mode is off. I've tried them all and the fan inside does not turn on.

My thoughts are it's the inside air handler, but then why would it work for 24 hours with a new motherboard?
Or a leak. Again, when the new motherboard was put in it worked, it wasn't charged until an hour after it was running.
Old 09-16-19, 05:13 AM
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Well, this morning it decided to work. I know it will go out again, but still have no idea what the problem is, and I guess no one else does either Now I have to convince them it wasn't actually working during the weekend.
Old 09-16-19, 07:00 AM
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Is this a home warranty company doing service?
You need a new tech. If he had to add refrigerant you have a leak. Or he diagnosed it wrong.
The boards and controls are very simple and easy to check.
So right now the condenser works but the indoor blower is inoperable, right?

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