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I have a comfortstar indoor unit model CM118B and i am

Customer Question
I have a comfortstar...

I have a comfortstar indoor unit model CM118B and i am getting an error code H4 the unit is in heating mode what could the problem be?

Contractor's Assistant: Did you double-check the thermostat's settings? And what about the filters?

Tstat set at 70 degrees out door temp is around 40. Filters appear to be clean

Contractor's Assistant: Do you plan on doing the work yourself?

If it is something fairly easy to do

Contractor's Assistant: Anything else we should know to help you best?

I don't think so

Submitted: 4 months ago.Category: HVAC
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Answered in 27 minutes by:
12/8/2017
HVAC Technician: Phil, Mechanical Engineer replied 4 months ago
Phil
Phil, Mechanical Engineer
Category: HVAC
Satisfied Customers: 6,938
Experience: Retired HVAC/ Electrical & Boiler contractor. Industrial
Verified

Hello, look on the wiring diagram glued inside the furnace blower access door, or on a large sticker on the outside of the blower access door for the error code read outs.

So far I do not see H series error codes in any recent models.

Most common problems are a bad pressure switch, dirty flame sensor, bad ignitor, bad high limit switch or bad printed circuit board. I can coach you through a diagnosis if you have a multi meter, and about 2 hours, you will get your hands dirty. OR

If you can tell me which direction you are from the center of the nearest city I will locate a well rated service outfit for you.

.

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Phil, Mechanical Engineer
Category: HVAC
Satisfied Customers: 6,938
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Experience: Retired HVAC/ Electrical & Boiler contractor. Industrial

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