Mini Split cleaning - indoor and outdoor

[Chuckanut]

I am the owner of a new Mitsubishi mini-split heat pump system. I haven't used it much since the latest weather has been very mild (mid 60's to mid 70's) and there isn't much reason to heat or cool the living area.

I just read that I should clean both the indoor units (I have 2) and the outdoor unit at least once a year. So I looked up how to do it. Cleaning the outdoor unit is not a big deal. Turn off the power at the breaker, spray some cleaner on the grills, fins and such, hose it off, let it dry, and turn the power back on. It sounds EZPZ.

But, the indoor units.... all I can say is WOW! They seem to require a degree in cleaning. The steps include:

• Put a special bib around the base of the indoor unit,
• remove the vent blades and outer shell of the unit,
• check for mold and other stuff growing on the inside of the units,
• attach a big with drain hose so the cleaning fluid and water can be directed into a big bucket,
• cover electrical parts to prevent them from getting wet,
• use a special lower pressure washer to spray water and wash the cleaner and dirt into the big,
• hope that it all drips into the bib runs down the hose into the bucket,
• take the outer shell outside and hose it off
• re-attach the filters, vent blades, outer shell and anything else removed,
• let it dry,
• turn the power on.

I am wondering what those who have had a mini-split heat pump do to clean it and how often. Or do you pay a tech to come in service the units?

 

[JoeWras]

This is the biggest negative of a mini-split

Yep. Been there, done that, also with a Mitsubishi. This indoor maintenance is a big negative and it is not discussed enough when mini-splits are brought up. To make matters worse, most of the units have these terrible "filters" that do little to nothing. I'd like to see a better filtering method on the indoor unit. It would solve this issue.

I wish I could give you a full maintenance experience, but I can't because here's the story...

I volunteer with a non-profit, and we do maintenance. We went to a facility that was shut for 2 months. The units were 2 years old. In the dining room, we set up chairs along the wall to talk. We turned on the air. One guy was getting agitated. We realized, about every 5 seconds, the unit was spitting out "chunks" of something that were landing on his head and neck. He got up and dusted off the chunks of debris that appeared to be mended by some biofilm, possibly mold. He was a bit unhappy.

With this experience, we added "maintain indoor blower" to our maintenance list. The guy assigned to it did what you did: searched and found youtubes. We didn't have the equipment, so instead, we took apart what we could. It was very difficult to take off the shell and blades. Nothing was obvious. We took off what we could, and wiped and vacuumed what we could reach, which clearly wasn't enough. There was just too much hidden, hence the wash down procedure you read about.

After this unsatisfactory experience, we informed the director that a pro needs to clean the 12 units in the building. He looked into it and told us to continue to do our best, because that maintenance was unaffordable.

The pandemic hit, finances got worse, and the facility had to be sold. End of story.

Good luck. I hope you find a good solution.

 

[Tom52]

I installed a Mitsubishi mini split unit in my garage just over 2 years ago. The indoor unit is model MSZ-GL24NA. Cleaning instructions in manual are pretty basic.
Turn off power at breaker
Lift front cover
Wipe cover with a soft dry cloth, or rinse it with water.
Remove Nano platinum filter: vacuum, wash with water, air dry - clean every 2 weeks
Remove Electrostatic anti-allergy enzyme filter: remove dirt by vacuum cleaner, soak filter and frame in Luke warm water, rinse and air dry. Clean every 3 months. Replace with a new air cleaning filter every year.

I will be installing a second Mitsubishi mini split in my enclosed lanai in a couple of months. The HVAC company will be at my house this Wednesday. I will try to remember to ask him what is normal for cleaning these units. I will likely get a in ceiling cassette system as they look so much better than a head unit mounted on the wall.

Since I only run the unit when it is really hot in summer and rarely at all during the winter, twice a year cleaning is adequate in my experience. And even then there is very little dust in the filters or on the cover. I have not seen the need to use more than a lightly damped cloth to wipe down and around the front cover.