On Sun, Jul 10, 2011 at 9:04 PM, Herbert Graf <hkgraf@gmail.com> wrote:
> The central air unit at my home has stopped cooling at around noon, on
> Sunday, the past 2 Sundays. It starts working again around 8-9pm.
>
> The symptom is the unit is "on", i.e. the condenser fan is running
> (including the furnace fan), but the compressor is not. The coolant
> pipes are both ambient temp.
>
> At around 8 or 9pm it starts working again, and works for the entire
> week.

If it happens at exactly the same time for two weeks, you can suppose
that it's a logic/controller issue instead of a mechanical issue.
Because the compressor works for the whole week except for 8 hours, it
would stand to reason that it really does work just fine.

Try manually enabling the compressor using the contactor that switches
on the compressor. I'm not sure how it's arranged on these units but I
guess you would probably be able to cause it to close with your
24/26VAC signal.

--=20
Martin K.
--=20
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