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Phil, Mechanical Engineer
Category: HVAC
Satisfied Customers: 7911
Experience:  Retired HVAC/ Electrical & Boiler contractor. Industrial
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I have a Thermocore 3/4 ton mini-split about a year old.

Customer Question

I have a Thermocore 3/4 ton mini-split about a year old. After a community power outage the unit started up at first normally. (Run light on inside unit, fan blowing...outside unit fan blowing.)
After about 5 minutes unit shut down and Error code is: EC with 7 flashes on the inside unit panel. Outside compressor lines show no differential temperature for inlet and outlet. Felt about ambient temperature.
How do I fix this? I do have a set of gages and MANY years ago I was the HVAC consultant for Amoco Oil company for industrial units. I have routinely check the charge on my old central air unit but have had little experience with mini-split units.
Submitted: 8 months ago.
Category: HVAC
Expert:  HVAC Guru replied 8 months ago.

Hello and thanks for using this service, if you have been waiting do not worry or get upset. I am HVAC Guru an extremely experienced tech on the site and I try to get to as many customers as I can. I just picked up your question now. NOTE it takes time for me to type research and add links so please wait for me to respond back I can only do this so fast. Secondly I am not paid anything until you rate my service good using the STAR RATING LINK at the top of your page, the money is paid to the site not me directly.

What is the complete model number?

Customer: replied 8 months ago.
Thermocore T125S-H109C
Expert:  HVAC Guru replied 8 months ago.

Sorry for the delay, that is a communication error, go to this link and go through the troubleshooting steps to rectify the error.


All I ask is please use the Star Rating Link at the top of your page before leaving, that is the only way I am paid anything through the site and that will also get you a DIRECT LINK emailed to you to get back to me! are greatly appreciated so thank you very much for using this service. If you have any other questions just post back to me here anytime!

Customer: replied 8 months ago.
The unit I have does not have any LEDs on the IPM board. The only light indicator is on the front panel of the air handler. On that panel there is a constantly lit "EC" and a led flashing 7 times followed by a long pause and then flashes another 7 times, etc. The EC stays on all the time. There are no leds of any kind on any circuit board of the air handler nor outside compressor unit. Your diagnostic flow chart does not apply as written for the Thermocline unit I have.
Please try again.
Expert:  HVAC Guru replied 8 months ago.

The code is the same whether or not yours has leds on the board or not you have a board failure on the unit

Customer: replied 8 months ago.
I'm sorry it is not a sufficient to say that even though I do not have what you told me to look for that i have a bad board does not fill me with confidence as to your familiarity with Thermocore min split units.
You gave me a specific sequence including leds that are not even there.
You have not identified what the specific code on my Thermocore unit means.
Apparently you either have not had experience with my Thermocore unit or do not have access to the repair diagnostic manual that applies to it
To send me a repair procedure that does not even specifically apply to my machine is not an answer.
Anyone can say it is not working and to keep on changing out about $800 worth of boards on a unit until it works.
With all due respect to your years of experience, you apparently can't adequately answer my question. If you can't find the answer specific for my machine, please direct my question to another expert who does know Thermocore machines and can answer.
Thank you.
Expert:  Phil replied 8 months ago.

Hello, just to let you know, Thermocore is not common at all, a less than 1/10th of one percent brand. most of such type units are made in china and often with no parts support. Neither the brand name nor the model number is ***** on Google... This is not the answer you need, just a comment. Even if you get a good diagnosis somehow, getting the part would most likely turn out to be an insurmountable problem. I wish that I could be more helpful. Thanks for trying us at Just Answer!

Customer: replied 8 months ago.
I hear what you are saying. I am a contractor.
One of my other 5 Thermocore units which I bought together failed within the parts warranty period.
Thermocore supplied all the components to my local HVAC source here in Charlottesville VA.
I would have called them again since the code was totally different but I had hoped that JustAnswer could answer and perhaps save me some money.
I used to work with older design units years ago but not mini splits at all.
My understanding from them was that the compressor is a Toshiba. The other unit lost a compressor pretty quickly after installation which Thetmocore sent a replacement compressor along with another main board under warranty.
I was impressed with the rapid response from Thermocore they did their job. As a consumer I can't be responsible for the rarity of these units but my expectation that a self proclaimed expert HVAC "Guru" should be able to diagnose is a normal response.
Thank you for your candor saying you can't answer.
I don't know how you good folks get paid but I can't justify paying for no corrective answer.
Is it possible totsend this question thread to another expert who might have had Thermocore experience or is JustAnswer at the end of their effort?
Thank you.

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