Mini Split completely corroded

[500lbs Guerilla]

Although this should have been more obvious, I want to post a thread about this since I don't see very much information about it on the forums. I've had multiple thermistor assemblies going out on my LG mini splits lately, and upon further inspection, found the inside of my indoor units completely corroded. I've traced my mind over and over to try and figure out what would have caused this, and finally it stumbled on me....SULFUR

Sulfur is can be extremely corrosive, and sulfur vapor can permeate into your air conditioners, dehumidifiers, etc and corrode various metal components and/or copper connectors. I'm finding that I will have to prematurely replace my indoor mini split units because of this.

Take precaution

 

[Seamaiden]

Holy shit! I never EVER would have thought of that, Guerilla. That's an expensive lesson, gotta thank you for sharing.

 

[Jalisco Kid]

How much sulfur you burn in a cycle for what size room. Curious what made the sulfuric acid not being a chem head. Good thinking there putting 2+2 together to come up with 5. JK

 

[We Solidarity]

I've been vaporizing sulphur at night since day 1, I know my humidity gets in the high 60s which means there is alot of sulphuric acid being created, but in four years I haven't seen anything in any of my rooms get corroded.

 

[Jalisco Kid]

I've been vaporizing sulphur at night since day 1, I know my humidity gets in the high 60s which means there is alot of sulphuric acid being created, but in four years I haven't seen anything in any of my rooms get corroded.

That seems a waste and I feel it would limit your growth.For how long,how much,in what size room are you doing that. 60% rh is considered just about perfect in my room. JK

 

[We Solidarity]

That seems a waste and I feel it would limit your growth.For how long,how much,in what size room are you doing that. 60% rh is considered just about perfect in my room. JK

sorry that probably sounds confusing...indoors I only run a burner for 4 hours or so, one or two nights a week. every month or so in veg and up to week 3 in flower.

 

[Myco]

HVAC professional here with a small bit to add...

Coincidentally, LG mini-split equipment is notorious for thermistor issues (among other problems.) FWIW.

Highly do not recommend LG equipment. The major suppliers don't even carry the line anymore.

Interesting about the sulphur though.

As for bang for your buck, Daikin. If money is not of concern, Mitsu. Widely available parts and customer support for both.

Good luck to you sir.

 

[500lbs Guerilla]

How much sulfur you burn in a cycle for what size room. Curious what made the sulfuric acid not being a chem head. Good thinking there putting 2+2 together to come up with 5. JK

About 8 hours every other day for 6 days, so 3 applications over the course of a week. This is during the 1st week of flower. I also run it for 12 hours two days in a row in between cycles to make sure the room is spore free before transplanting. Probably overkill. The room is 12x26 with low 7' ceilings. I've run this by my HVAC and he agrees that sulfur is a very possible cause of corrosion. I've found a couple posts on forums about coils corroding due to sulfur, but it doesn't seem common. Even 2+2 equaling 5 is closer than the 0+0 = 6 that I had before. Perhaps theres another cause, but if not the sulfur, then I'm at a complete loss. I also use pvc trellis frames with steel eyelets to tie the string to, and the eyelets are also showing corrosion. RH is a steady 60%.

HVAC professional here with a small bit to add...

Coincidentally, LG mini-split equipment is notorious for thermistor issues (among other problems.) FWIW.

Highly do not recommend LG equipment. The major suppliers don't even carry the line anymore.

Interesting about the sulphur though.

As for bang for your buck, Daikin. If money is not of concern, Mitsu. Widely available parts and customer support for both.

Good luck to you sir.

This is very interesting about LG being notorious for thermistor issues. Luckily its a cheap part and an easy fix. I am in Santa Cruz County, and most of the local shops are carrying LG mini splits. I will look into Daikin. I know Mitsus are great. Whats your opinion on Friedrich?

 

[Myco]

This is very interesting about LG being notorious for thermistor issues. Luckily its a cheap part and an easy fix. I am in Santa Cruz County, and most of the local shops are carrying LG mini splits. I will look into Daikin. I know Mitsus are great. Whats your opinion on Friedrich?

I find that somewhat surprising... are you referring to wholesalers or...? We were an LG "dealer" for about a year, and after about a 30-40% failure rate we stopped selling them, and within a few months' time the parts were only available by factory order, we couldn't find parts/equip anywhere within the PDX metro area. Maybe things have changed, but even with the new company I am involved with, LG is a dirty word.

I can't provide any opinion of Friedrich simply because my experience with them is very limited. But, Daikin is roughly 70% of the cost of Mitsu and has been very dependable, in both my personal and professional experience. And better low ambient cooling abilities, which is very important in my area, probably not as much for you.

Do you have any pics of the corrosion? My apologies if you've posted them and they're not loading for me.

My opinion of the sulphur causing your problems may be slightly skewed, because I have worked with a few folks with fairly large, sulphur-burning operations and have yet to see it. But, it also may be connected to the particular materials and manufacturing process of LG coils. There are a couple types of known corrosion in coils, caused by everything from organic compounds in dust, to known offgassing issues from paint/carpet/etc - and most manufacturers use special coatings on the coils to combat this...

Not that I am saying sulphur isn't the culprit, you just have me a bit curious!