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My setup:
I have three C&H brand 9k head units upstairs in 3 different rooms. One 18k slim duct unit downstairs. And a 48k compressor outside.

The scenario:
It's 50° outside.
The three 9k units have a set temp of 65°. The temp in the rooms is 70° and they are idle and aren't producing heat. The 18k unit is off and the room temp is reading 68°.

The issue:
If I turn the 18k unit on and up to 72° it starts producing heat but at the same time the 3 9k units also start producing heat and don't stop even after they all hit their respective set temps.

It's 76° and climbing in all of the 9k unit rooms even though their set temps are still 65°.

Specifications:
The same issue happens when using the head units as the thermostat or the remote as the thermostat.

The question:
Why is this happening?

isherwood
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Landoperk
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  • @ Landoperk, IDKWYATA? Please use the full words to describe your issue. At least at the beginning of the question. Acronyms can be confusing. – RMDman Sep 30 '23 at 11:46
  • Should we assume you're talking about mini splits or soemthing? – Huesmann Sep 30 '23 at 13:00
  • Heat-pump tag, head unit, duct unit, compressor, C&H is a brand... – Landoperk Sep 30 '23 at 15:27
  • @Landoperk I [edit]ed that info directly into the question (where it belongs) because it was very confusing and it took time to find the info down here in the comments. You're free to [edit] your own questions/answers any time you'd like to add more details, clarifying info, etc. – FreeMan Oct 05 '23 at 15:25

1 Answers1

4

The issue has been resolved.

Root cause
The culprit was a faulty management board on the compressor.

Diagnosis
One of the terminals was throwing irregular voltages. The manufacturer said this could have been caused by a defect from the factory or an unregulated power surge.

Fix
Replaced the board.

Future Considerations
Installed surge protector at compressor unit.

Landoperk
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