My glycol turned green...

[haveitall]

I have a chiller that I filled with Glycol about two years ago, and it is getting progressively more green with age (started clear).

I have new glycol to replace it - but I'm trying to figure out how to clean the unit before I swap in the new glycol. Any suggestions? Any reason my glycol went bad so fast?

Unit is an SS Brewtech

 

[matt_m]

Mine did that. With the unit off, I rinsed everything really good with hot water then circulated water with a little bleach for a day. After rinsing thoroughly I refilled with glycol/water mix and its been fine since.

 

[Golddiggie]

Was it always running, or did you turn it off at times?? IIRC, it's best to keep the glycol solution cool than turn the chiller off for days/weeks/etc.

For cleaning, once drained, try rinsing it out really well. You might want to look at getting some algicide and using that. Probably a good idea to reach out to SS Brewtech to get their ideas on it before you do something like that.

 

[haveitall]

I keep it running, but did turn it up to about 40° when not in use. I figured that was sufficient to keep it fresh (but clearly not...). I've got the question into SS about it - I'll report what they say. I was thinking the bleach idea might be good - though not sure what that could do to components. I don't really want to run it at 30 degrees forever - it makes a lot of noise.

 

[haveitall]

And for what it's worth - the transparent hose on the front (that lets you see the water level) is what is green. The actual glycol looks ok.

 

[Golddiggie]

Did you pull a sample from inside the chiller to see how that looks? If it's just the tube showing the color, it's possible it's aging in a way that gives it a tint.

The IceMaster Max2 I had also had the 'sight tube' in the front. While it's a neat idea, I found it pretty much useless. If you do end up draining it, you might want to just plug where the tube is and remove that from the mix completely.

 

[haveitall]

10 points to Golddiggie...

I pulled a sample. The stuff is crystal clear, with some green floaties. It looks like those are from the top copper tube which is partially out of the glycol (and now all green). The site tube seems to attract the green flakes. I had just assumed the green was in the liquid.

Incidentally, the SS response was to use water/vinegar to wash it - nothing more harsh.

 

[Golddiggie]

If you're sure the floaties are not something living, then just keep using it. You might want to check the concentration of the solution to make sure it's not changed enough over the two years to make a difference.

I have some glycol in reserve from when I filled up my Max4 chiller. At some point I'll get enough to do a fluid change. Not a huge rush just yet though.

 

[matt_m]

Interesting. I don't recall paying any attention to what it looked like when I pumped it out. I wonder if copper corrosion deposits itself on silicone tubing?

 

[haveitall]

Yes - looks like the copper corrosion likes the tubing. There is some on the tubing to the conical, but less. That tubing sits empty most of the time though. I didn’t really notice it is a bit green until I looked closely.