Mini Split quit last night at -8 deg F, first issue in 4 winters since installing. need heat

Caleb

Have the Mitsu Hyper Heat 18K BTU model. Should be 100% heat to 5 deg F, 75% heat output to -13deg F is the MFG rating. Read through the service manual and tested the unit, says the outdoor unit failed with error code 3, which is a thermister. Ready to go outside and troubleshoot, but is there any quick fix to maybe put a hair drier on the components to warm up and maybe get it working again? Im sure the issue is related to the very cold day/night yesterday, and now it won't start up.

thanks for any tips from ones who have dealt with this before

GW

Yes if you have the tools you can ohm the sensor and see what's up. These things happen, I hope you have some back up heat.

Gw

Caleb

Thanks tried a hair dryer to warm up the outdoor unit but no joy yet. Need to take off the covers to get to the board. Checked 240VAC and 12VDC are both good.

Now when I start the inside unit, it blinks 6 times on top light, think that indicates bad serial connection to outside.. but when I hit remote reset to pull up last code, it beeps 3 times indicating thermister. Not sure which one is which.

small house, have 2 electric space heaters that are getting us to 60 degrees, good enough for now until we fix the minisplit.

just need to figure out if its 6 or 3 blinks that I should be running down.

Caleb

6 blinks on outdoor unit says its OVER PRESSURE.. could it be plugged stop valve?

GW

I'm stumped, maybe exv isn't cooperating.

Did you try killing power and resetting power after a few minutes?