Honeywell Chronotherm III - AC

[alex4misc2]

Hi there

My Honeywell Chronotherm III shows "- AC" and blinking "TEMPORARY". Any
ideas why and what can be done to fix it?

I changed the batteries - it did not help.

Thank you in advance, Alex.
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[Dr. Hardcrab]

Post by alex4misc2
Hi there
My Honeywell Chronotherm III shows "- AC" and blinking "TEMPORARY". Any
ideas why and what can be done to fix it?
I changed the batteries - it did not help.
Thank you in advance, Alex.

AC means there is no power to the thermostat. It could be that the circuit
breaker is off or tripped, or your low voltage transformer (to your air
handler, furnace, or whatever you have) is bad. Does the fan come on when
you switch the fan switch from 'auto' to 'on'? If not, you have a power
problem (in other words, the 'AC' does not stand for Air Conditioning).

The flashing 'temp' means that you have adjusted the temperature away from
whatever you have programmed.

[m smith]

replying to Dr. Hardcrab, m smith wrote:
Good information, thanks. In my case, the cover on the furnace was open, so a
safety interlock preventing furnace operation caused the thermostat display to
essentially disappear, but it intermittently and weakly displayed the -AC
code. Attaching the furnace cover solved the problem for me.

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[Bubba]

Post by alex4misc2
Hi there
My Honeywell Chronotherm III shows "- AC" and blinking "TEMPORARY". Any
ideas why and what can be done to fix it?
I changed the batteries - it did not help.
Thank you in advance, Alex.
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Alex,
I am somewhat of an expert on thermostats. If it is flashing "- AC" it
is quite a simple fix. It just means the Air Cond will not work.
Usually you just have to put in fresh batteries.
If it is flashing "TEMPORARY" it just means that .....temporarily, the
A/C will not work.
Both messages are really working together. You often have to replace
the thermostat if both messages are showing.
Bubba

[Yer Mom]

replying to Bubba, Yer Mom wrote:
This is wrong! The "-AC" on the Chromotherm III display means the thermostat
is not getting the 24V AC power it needs to function. It has nothing to do
with Air Conditioning. (This, IMHO, is absoultely horrible product design...
but that's what it is :-))

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[unknown]

Post by alex4misc2
Hi there
My Honeywell Chronotherm III shows "- AC" and blinking "TEMPORARY". Any
ideas why and what can be done to fix it?
I changed the batteries - it did not help.

Go to your local big box store and buy a can of electronspray.
Carefully remove the stat and spray the red an blue wires.

[big_dgreen]

big_dgreen had written this in response to
http://www.www.thestuccocompany.com/hvac/Honeywell-Chronotherm-III-AC-31748-.htm
:
Temporary flash typically means you have a programmable t-stat and your
overriding the temperature and it will reset itself back to program after
about 2 hours.

AC could be a diagnostic code from the air handler to the t-stat to alert
you of a problemm.

I agree with the info about possibly losing low voltage from your
transformer. If the ac is not running you should call a service man.

If it is running, it may be a filter reminder, but I doubt it. I'm not
familiar with the chronotherms layout.

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Post by alex4misc2
Hi there
My Honeywell Chronotherm III shows "- AC" and blinking
"TEMPORARY". Any
ideas why and what can be done to fix it?
I changed the batteries - it did not help.
Thank you in advance, Alex.
-------------------------------------
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http://www.thestuccocompany.com/
Building Construction and Maintenance Forum
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and RSS access to your favorite newsgroup -
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counting!
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[msstockton]

replying to big_dgreen, msstockton wrote:
Mine only happens when i go from air to heat. It gets all screwed up and I
can't get it to change back no matter what I try

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