Leaking Beermaster

[Andy AC]

Hello guys, have any of you had problems with beermaster evaporators rotting out/leaking ?
I've been called out to this system two or three times in the last 4 months or so, and without much searching found leaks on pipe work, valves etc, easily sorted each time. Anyway this time I got me nitrogen bottle out so i could test the old section of pipework as I thought this is where the latest leak would be, but nothing. I gave the return bends on each end of the evaporator a spray and found leaks on 5 different return bends, some with multiple leaks on each end of the coil
The evaporator is only 14 months old
If you run your finger over the returns, the copper is just rubbing away.
This is what caused the demise of the old evaporator but was in service for years before with no major problems.
There is quite a lot of rust/corrosion bust what would cause the copper to rot like this? . The unit is in a below ground cellar with all the usual stuff lying around such as erm, beer, the odd flash cooler or two and more beer , nothing unusual.
The only unusual thing about the installation is that some years ago, the condenser was changed for a L'unite Sylensis running on R404A, and of course the expansion valve.
I have spooke to NRS but as it is just out of warranty, all they want to do is sell us a new evap.
Am I unlucky ? or have some of you experienced the same problems on these?

Andy

[Andy W]

I had a distributor that can only be described as a sieve leaking on a 18 month old Friga Bohn, the manufacturer was not interested and would not sell me a new distributor, I had to remove one from a scrap evaporator and fit that, the customer was absolutely furious but I stood all the costs as a goodwill gesture.

[old gas bottle]

if there is alot of corrosion visable it may be that there is a nasty natual chemical in the cellar, maybe something like amonia,never heard of it before only on maggot fridges and vegatable stores with onion and alike,just maybe bad kit.

[Temprite]

G'day

Put "evaporator pitting" into search engine of this site.

Some information there.

[Andy AC]

As I mentioned before, the condenser is a L'unite silensys - H49Z R404a. The beermaster evaporator is a BME134/34 with a R404a valve fitted. I was wondering if when the evap is replaced, that i could change it for the R407c equivalent, and charge the silensys with R407C insted of R404A so i don't have to muck around changing the factory fitted exp valve.
Any more thoughts / advice greatly appreciated.

Andy

[Andy AC]

New evaporator installed about a year ago, sprayed with alleged coil protective coating supplied by climate center with the new evap. Went to check on the unit after call to noisy condenser and found that the copper corrosion on the return bends is well underway again.
The only thing we have found different about this cellar is the ceiling is not insulated at all and they have a wood burning open fire almost directly above the evap end of the cellar. Do you guys think this could be a possible cause? Is there anything else we could spray or paint on the exposed copper? It only affects the copper that gets wet- the liquid line and any other copper pipes in the cellar are fine.

Andy

[Grizzly]

Hi Andy
It might sound stupid but you could always try WD40.
And see how that goes?
Grizzly.
As to where your contamination is coming from "haven't got a clue" Sorry!

[Brian_UK]

Wood burners generate acid fumes but the question then is "How is it getting into the cellar?"

Old chimney opening in the cellar that is no longer used ?

[Electrocoolman]

What about the beerline cleaner they use. I've also seen MILTON used in cellars...this is bleach / hypochlorite. I'm sure this attacks copper.
Is there green verdigris on tubing?

[Andy AC]

Brian - the exposed floor boards of the bar above is the ceiling of the cellar, so its not air tight. So i upoose it must be picking up chimney fumes for a few months a year.

Andy

[Brian_UK]

Brian - the exposed floor boards of the bar above is the ceiling of the cellar, so its not air tight. So i upoose it must be picking up chimney fumes for a few months a year.

Andy

I don't suppose you're getting wood ash down there as well ??? Hopefully not.

[Andy AC]

Its gone again Got a call this morning from bar manager from the hotel saying he's just turned the unit back on again after defrosting all the ice off the coil and he was concerned about a hissing noise so he turned it back off. First thing I thought was the copper had rotted on the return bends again. Got there, pulled the covers off expecting to find smell of gas & oil everywhere, but nothing. I fired it up and as soon as the solenoid valve opened, big, big loud hiss.
Found a large screwdriver shaped puncture in back of coil - muppet bar staff
Couldn't sensibly cut out and remove section of coil so I went for the good old blob of braze trick, not ideal but does the job. Went back upstairs, got the nitrogen out, pumped it up, went back down to the cellar check my repair. My crappy repair held but when I sprayed the return bends on each end the coil, I found seven or eight leaking like a sieve.
I think I'm going to rip the system out a put a marstair or qualitair in, at least on the marstair you can change the evap coil easily.

Andy