Mini split cleaning

bio_guy

I have 5 questions to ask of experienced people.

1) Do you like the mini split cleaning kits? I am talking about the bags that hang on the units to catch water and cleaner. If so, what brand?

2) What kind of coil cleaner do you like? I am getting tired of the spray cans and I follow with a tank sprayer to rinse anyway.

3) I have Mitsubishi MSZ indoor units. I'd like to pull out the blower wheels to clean them. I have disassembly instructions that have you taking the blower motor off, lots of electrical components from the right side, removing an unidentified "corner box". Finally, I am instructed to remove the three fixing screws from the left side of the heat exchanger and loosen the set screw for the line flow fan (blower cage), lift the heat exchanger and pull the fan out to the lower left. It seems to me that all I really have to do is remove three fixing screws, loosen the set screw, shift the heat exchanger and pull the cage out. Any comments?

4) I'd like to get the drip tray out to clean that, but I have not yet tried to figure out how to do it and it is not covered in the manual that I have. Any tips?

5) I am having trouble finding high quality small brushes to vacuum the fins in the HX. I bought some small brushes, but the bristles pull off and stick in the fins. Talk about counter productive! I found a Mitsubishi kit listed for this, a "Quick Clean Kit", MAC-093SS-E. Apparently it is, however, not available in the USA. Can anyone recommend some quality, small brushes?

Thanks for reading!

aircooled81

Mitsubishi tech support told me many years ago, a dirty blower wheel can cut the airvolume by 40% or more. Good thinking cleaning the wheel.
when you remove it, replace the bearings, it's a bit of time to pull those wheels, so while your in there replace the bearings, when they get old they start to squeek.
you can try compressed air to blow the evap out, just dont bend the fins on the coil.
i just use a squirt bottle, and any cleaner that doesnt harm aluminum, and doesnt leave a lousy odor. simple green, calgon evap rinseless foaming spray is nice.
yes, vacuum the surface before wetting it down., get the initial crud off.
because air is entering the surface you see, it isnt as likely the back side of the coil is as dirty as you think.
never heard of a bag to catch the water, i just take my time and make sure i dont flood the pan.. .i know they are so small!!

hope atleast one of these ideas helps.

Brp814

I saw the cleaning kits at the 2014 AHR show in NYC, pretty cool. I have not used any, but have cleaned a few of the mini splits out. To do it right takes hours. I did not pull the wheel, but cleaned it as best as I could.

bnjmn

I use the coil jet portable pressure washer and ductless cleaning kit. Works great... Payed for itself in just a couple uses...

bio_guy

Thanks for the updates on cleaning kits and suggestions for cleaning. I found this clip recently that may help.

I'm waking up this stale thread because it looks like Mitsubishi has stepped up with some instructions. They could do better by putting them directly on their web site. (The link mentioned at the end of the video is informative, but does not offer any other real maintenance help akin to what the video offered.)

Looking into thoroughly cleaning mine, I spent, literally, hours looking at my service manual for my MSZ-GE06NA units and partially disassembling one on the wall before I gave up. What a frustrating day. In the end, I did conclude that I should be able to remove the blower by backing off the set screw on the squirrel cage and removing the three screws on the left side to lift the coil, but I was too chicken to do it without specific instructions to do so. The manual lead me to believe that I have to remove all the electronic controls, vane motors,..., and the blower motor/bearing.

Jeff is my new best friend:

https://www.youtube.com/watch?v=OiEcHHzz8YU#t=130.2113363

bio_guy

I bought a SpeedClean bag. I am reasonably happy with it so far. I took apart one of my Mitsubishi high wall appliances. Off came the main cover and louvers. Removing three screws on the left and the set screw on the squirrel cage allowed pretty easy removal of the cage just like in the vid. There are three tabs and some tugging and pulling to remove the condensate tray. I removed the horizontal vane motor as well as it looked like it would be easier to get it out of the way than to maneuver the tray around it, two little screws and it can be pulled out of the say and taped to the right side of the unit to preclude stress on the wire bundle.

The tray and squirrel cage were pretty nasty as were the surfaces around the cage where soggy stuff was flung. That includes the safety cages in front of the vertical louvers. It is pretty groady in there. I knew it would be because I had looked at the blower cage with a flashlight.

Cleaning the cage was super easy and much more thorough out in the driveway. I vacuumed it off. Still looked bad. I don't know if that step was worth the trouble. I soaked everything in neutral detergent after hosing off with a typical garden hose-end sprayer. After spraying, soaking and spraying, the cage looked like new. I cleaned the main case, louvers and condensate tray with a soft cloth or brush in the same detergent. I gave everything a 10-minute treatment in diluted bleach, rinsed and dried them off with a soft rag and left them in the sun for an hour while I made and had lunch.

Indoors, on went the bag. I cleaned the coil with $self rinsing foaming spray cleaner$ where stuff was visibly stuck between the fins. It took repeated applications. Some gunk came out but some tiny bits never came out. Rinse and rinse. I cleaned the rest with Evap Power C that was the choice at the local supplier that sells to the public. Rinse and rinse; Why cut corners and not rinse when I've gotten this far into it!

Reinstallation of the blower cage was easy. Reinstallation of the condensate tray took a while. Lining the ends up to the shallow grooves to its sides that they fit into was not easy to figure out and it was not obvious what I should have checked the fit more carefully before I wiggled it out. The angle of attack on snapping it in is not obvious either. I must have spent a half hour at it, but it seemed like hours, of course. (I took it out again the following week to see if I could put a copper wire underneath the coils to suppress microbial growth and found it much easier with experience.) The rest was a snap.

Looking to the future, I have a couple of high wall appliances that are close to the wall on the left so I might not be able to pull the cage out as easily. I think that they will come out underneath and one of them has a big exhaust fan in that wall close to where the trajectory of the cage would naturally go when pulling it out the side. We'll see. Installation location choice should be made with attention to this maneuver. Give 'er about 26 inches on the left if you can! If that can’t be done, the blower cage will have to be cleaned in place, or the whole appliance removed after pumping out the refrigerant and disconnecting.

Back to the newly cleaned appliance. I wanted to re-set that appliance on the wall because I found that the drain pigtail goes from the right side all the way to the left side within the unit before it enters the wall. Poor drainage plan, I think. Ironically, the day I got everything assembled and ready to start, the appliance to be attended to suddenly started to rain copiously all over the floor underneath it.

I got into the wall to reroute the pigtail and the hose, but the hole in the wall does not line up perfectly in the horizontal dimension and the pigtail has a fraction of an inch climb before it enters the wall. I want to raise the appliance a little, and shift it to the left a little. I had to straighten the mounting plate a little. Due to my ham-fisted handling of it, I bent it a little at the top at the tabs. I also wanted to give the whole thing a slight lean to the left so it will drain more completely. It seemed to have a slight lean to the right to begin with.

I installed some temporary "hooks", made from some scrap brackets I had in the garage, in the wall and moved the appliance up and hung it onto those. I managed to get the mounting plate off and reposition it. (I was considering making a sling of sorts to support it from underneath.) It is all done and, amazingly, it still works. Good thing since we have 100+ heat indexes this week.

I am planning on redoing the condensate lines in the stud spaces with hard pipe where I can do it easily. That will be for at least 4 of seven units. The installers used a mix of corrugated tube on some units and transparent flexible plastic tube on others. I don’t like either of them. I could not run my string trimmer “snake” down the corrugated and the plastic seems to tend to collapse where it is curved. The snap-on drain pigtail on the units is corrugated as well so difficult to snake from the beginning of the drainage at the tray.

I am optimistic that more regular cleaning of the coils and tray will keep drain lines clear of clogs for the ones that I can’t get into the walls easily. We’ll see.

bio_guy

Update: getting the squirrel cage out with little clearance to the left is really no problem. The cage can drop down after pulling it to the left just enough to clear the motor shaft. I now believe that the installation instructions cover the required clearance. I really have very little material on the fins. There are little areas, very small, that have some clogging that foaming cleaner will not remove. (Most of the buildup problems are on the blower cage.) With the one that I worked on this weekend, I tried rubbing the bits a little with a q-tip. That seemed to help, but I was far along in the process when I decided to tray that (last rinse. I think that in the next one I tackle, I will try that earlier and work at it a bit.