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Mitsubishi 1/2 ton head not powering up

Hello, just wondering if anyone has had any issues with a brand new Mitsubishi head not powering up. I have a 5 head system that was just started today and 4/5 the heads powered up just fine with no issues. The 5th head is not being recognized by the branch box, nor will it run in Emergency Operation Mode. There is power to the line terminals.

Thanks in advance! I'm hoping not to have to pump down the whole damn system and make a warranty claim, but I can't seem to find a fuse or anything internally I can mess with. The installer isn't really troubleshooting it, just wanting to send it back.

Asked by Mike M
Posted Nov 12, 2017 11:03 PM ET


2 Answers

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I believe I got it all figured out. Accessed the boards and pulled the fuse, reinstalled and I have powers. Now I need them to fix a leak on my liquid line to the branch box. On a measured system like this, can you still use super heat etc. to determine the charge I'm losing. It looks like the copper was slight bent going into the compression nut and didnt fully seat

Answered by Mike M
Posted Nov 13, 2017 1:01 AM ET


No, you can't use superheat...the installer needs to fix the leak, weigh out the refrigerant into an empty tank, then weigh back in with the correct amount as spec'd by the manufacturer.

Answered by John Semmelhack
Posted Nov 13, 2017 2:57 PM ET

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