Mitsubishi dripping condensation

[MushCreek]

...from the wrong place, that is. Backstory- My Mitsubishi mini-split started losing effectiveness last year. Further investigation lead to a leaking coil on the inside unit. Of course, Mits doesn't make the same head unit anymore (after just 5 years) so I replaced the coil itself. The part was slightly warped/bent, but I managed to get it back together, and it cools great. But- sometimes it randomly drips condensation from the outside of the unit. It's quite hit-and-miss; sometimes it will go weeks without dripping; other times it drips all day. Yesterday, I McGyvered a trough out of sheet metal to catch the drips and funnel them to one one spot for collection.

I can't figure out where the problem is. My best guess is that it's touching somewhere that it shouldn't, causing the condensation to wick onto that surface instead of dripping into the designated internal drip pan. Yes, I've checked the drain tube, and it is clear. It continues to drip outside as well as inside. Once cooling season is over, I'll take the cover off and see if I can figure anything out. I'm NOT taking that thing all apart again! Worst case scenario- I'll eventually replace the entire system. My HVAC guy said these things don't last all that long in his experience.

Anybody seen this, or have any ideas?

 

[LS6 Tommy]

Is it a cassette unit? My experience is they frequently drip. I can't stand cassettes.

Tommy

 

[rlitman]

Yeah, dripping is a notorious issue with cassettes.

If the coil was bent, maybe it's not sitting right in the pan?

The only dripping I've gotten from my mini-splits was due to condensation on the vanes in extremely high humidity.

 

[MattT]

Might be insulation on the low side line that didn't get put back on? Or a baffle of something allowing cold air to leak where it shouldn't and cool the case down to the dewpoint.

 

[MushCreek]

It's in the wall unit itself. No insulation in there. The refrigerant lines are insulated properly. This is a stand-alone wall unit, not a built-in type. It never dripped until I put the new coil in. I think the coil being bent is causing it, but I don't know how to fix it. I tried straightening it a bit before putting it in, but it wouldn't budge. I didn't want to crazy on it for fear of damaging it. In hindsight, I should have sent it back for being damaged, but it went in OK, and doesn't leak refrigerant. Of course, its in my dining room. If it were in the shop, I wouldn't care.

 

[jjrbus]

Keep in mind I am not an AC tech, just another homeowner trying to get by. If I was in that situation I would take my shop vac and put something in nozzle to act as a filter and vacuum out the drain line.

I would want something white like a fine mesh, light colored nylons, something, to show if anything came out of line. Here in Fl vacuuming drain lines can be part of regular maintenance for AC.

 

[PoorOwner]

I think you may be right it is touching something it is not supposed to. I know you had to bend the tubing to get the new coil into the unit, just how exactly were one supposed to do this factory perfect??

You may want to try to run it without the cover and see if it drips out of the pan area.

 

[SALIV8]

Do u have any pictures?

 

[MushCreek]

First thing I did was check the drain line. I don't want to mess with it too much in August in SC. When the cooling season is over, I'll pull the cover off. The control panel kinda dangles, but I guess I could run it with the cover off. I don't have any pics. There's a smooth panel about 3" wide, and it drips along the outer edge of it. It's random along the length of it. That's why I made an external trough; no matter where it drips, it goes in the trough, which then guides it to a bucket. Works fine; looks like ****.

 

[fitter30]

For time being try running the fan on high rather than auto. In the fall spray diluted evap coil cleaner or dish soap on the coil. If theres any dirt or oil on the coil this might be redirecting the condensate from running down the coil on hi humidity days.

 

[WIKDRacing]

I am having the same problem with a Senville unit leaking on the inside. It has leaked so much that I have now had to pull the cabinet down that was below it and tear drywall out due to a large mold area. I am about to pull the rest of the cabinets down, removal all the drywall/insulation from that wall just to ensure all the mold is gone (Wife has a severe mold allergy).

I have had an HVAC company take a look at it and they said two months ago it was the small amount of insulation on the copper lines. They added more behind the unit. Condensation continue. Came back out yesterday and said the same thing. I am at the point now I want to just remove it and put in central air in the small space I had this unit.

It's very frustrating and expensive to have to redo this wall and I don't want to have to continue this on a yearly basis.