I can't speak for yours, but my condensate pump has a 10 year parts and labor warranty, according to Munns, in writing. I have no doubt that it is not a Mitsubishi part. Who Munns get reimbursed from for warranty repairs, if anyone, is of no interest to me. I would not call Mitsubishi for a warranty repair - I would call Munns, their authorized dealer.

Good luck same thing happened to mine. Compressor. $$$

Capacitor. If it was a condensate pump issue the unit would be flooding inside your home.

It was Munns who told me it was the pump. I will definitely get another diagnosis and quote.

Try Sun Kool. We have been using them to service our main A/C unit for 15 years and they installed our new A/C last year and installed our mini split A few years ago. We find them to be honest and knowledgeable. I'm sure they could look at yours and advise you.

For the record you do not have a ten year warranty, you have a one year warranty with a nine year extended warranty which IS NOT from the OEM. The point of me mentioning this is the extended warranty, a contract, can cover non Mitsubishi parts. Read your service contract which was mailed to you approximately four weeks after the installation.

The premium for this extended warranty was built into the original price. In today's dollars it added about $265.00 to the price. You can/could of opted out of it.

Perhaps you have an Aspen mini white pump
 

Check that model out in Amazon to see if that is the one you have. They cost about $160 for a replacement pump. They are easy to replace. They also require periodic maintenance at 6 month intervals. Remove the front cover, unclip the reservoir and clean with a bacterial cleaning solution. Your problem may be that the float is stuck in the up position causing it to run continuously. Clean the float and install with the magnet facing upwards on the float retainer.

Mini-split Service
 

I use Tropic Air Solutions. Father and Son Bruce and Cory have taken good care of mine.
352-321-6656

Try to find out which company installed the mini-split by checking with your County's buildings dept. since a permit would have been needed. That company can then inform you of the warranty on your unit. I use Munn's for the maintenance on my home HVAC system and United Refrigeration in Ocala (aka United Heat & Air) for my Mitsubishi mini-split. I have been happy with both companies.

It sounds like the condensate line the pump pumps into may be plugged causing the pump to continue running. You may want to consider having the unit cleaned and checked. Check drain lines, check drain pan, check outside where the line drains out may be plugged with grass or dirt causing the blockage. On some of these systems the pumps were located above the ceiling in the attic space making it difficult to service. You can call DeSantis HVAC service 352-330-4433.

Thanks so much. The unit has been serviced - twice since it started to hum.

Where does it hum?

If it is inside it is not the capacitor.

Munn’s Electric