"Bluing" of Plaster by heater

[tcjern]

I just had a pool guy tell me that my old Minimax heater has brass and copper header and heater exchange, and that this ruins the plaster. This process is called bluing of the plaster. Is this true? Should I replace ASAP?

Obviously, I'm very concerned. I just re-plastered like two years ago.

P.S. This heater is even before it was Pentair branded, though I can't remember the name label at the moment.

 

[jblizzle]

If you maintain balanced water, there should not be a problem.

If you drop and maintain the pH way too low, that can erode the copper and put it into the water and if too much copper ends up in the water, it can stain the pool surface.

Just keep the pH up in the 7s and no worries.

 

[Pool Clown]

I would immediately go out and buy a test kit, and begin to monitor the Ph. Heaters wont "Blue" the plaster without human interference. Three things come to mind that may do this. Too low Ph (as stated above), Improper use of certain algaecides (improper dosing), and high flow rate or too much water being pushed through the heater stripping or eroding the copper off the exchanger (>120 gpm). Having your pool guy tell you what he did is a red flag. Most, if not all heaters for the exception of CuNi have copper internally. His comment makes me think he did something and is covering himself by warning that your pool may develop copper sulfate staining in the event that he couldn't correct an over acid/ algaecide dose in time. That's why you should test the Ph independently from his test, and see where your Ph really is.

I dont know, maybe he told you that because he wants to sell you a new heater, or he doesn't want to work on it? Granted, the Minimax is not at the top of the heater heap, but that's no reason to get you to change the heater through deception. If your heater is a little long in the tooth, fine, there is no shame in not wanting to work on a dilapidated heater, he should at least be upfront with you, and let you make your own decision.

Please Note: I have no idea what condition your heater is in... The above, for all intents is speculative. I cant see your equipment. My job here is to give you the tools you need to be as informed as possible so you are not taken advantage of, or rather sold something you may not really need.

Triton Purex is the company that used to make that heater.

 

[JamesW]

Pac Fab made the minimax. Pac Fab was acquired by Pentair in 1999. That puts the heater at more than 15 years, which is pretty good.

Edit(1) I think the Pool Clown is correct that it was Purex. Pac Fab acquired Purex. So, originally, it was Purex. But then it was Pac Fab and now Pentair.

Edit(2) I think that PacFab used the Purex brand name on the heaters. I don't know if Pentair used the Purex brand name on the heaters.

 

[tcjern]

Thanks. He actually had not worked on it. Only saw it in pics that I sent. My PH is usually in the 7.2 - 7.8 range and I monitor it. Max flow is 100 gpm when I run for the spa. Perhaps he was pushing a new heater (not a bad idea considering the age), but I already have to replace my filter.

So no urgency. Thanks for the replies.

 

[jblizzle]

Is all 100GPM going through the heater? It might be worth considering adding a heater bypass so that less flow is forced through the heater (not sure if the older heaters had internal bypasses or not.

The bypass could simply be a pipe between the heater inlet and outlet with a valve in the middle. Leave the valve all the way open and you would have less than 50% of the flow through the heater, or slightly close the valve to force a little more through the heater.

A little more complex, would be to add what I described above, but also add a valve on the heater inlet and exit that would allow you to shut off the flow to the heater completely when you did not need it running or needed to work on it (or replace it).

 

[tcjern]

Well, I have no bypass, so yes. What is the maximum flow rate through them? Thanks for the advice.

It is Purex branded. I remember now that its been mentioned.

2nd point. The pool guy also (from the pics) said that my Intelliflo VF should have high temp unions on them (mine do not). Is this correct? I am pretty sure that the solar people, who put the pump in when I did the solar, didn't do a very good job. In the pic here you can see the odd plumbing on the top of the pump. Wish I had known more then to complain.

 

[JamesW]

There should be a label inside the door that has the make, model, serial number and date of manufacture (Assuming it’s still legible).

Does the heater work?

Do you have reason to think that the heat exchanger is substantially eroded or corroded?

Is there evidence of copper in the pool (staining etc.)?

 

[tcjern]

Heater works. No evidence of copper. I see no evidence of copper on the pool.
It is the Purex MiniMax 400. So I think that I am fine for now.

 

[Pool Clown]

If you have had that heater for 12 years in that configuration, and you have no staining, leave it. Wouldn't worry about a bypass now. MAYBE when you get a new heater, but i doubt it. You would have had a problem by now if flow through that heater was an issue.

 

[ps0303]

I just had a pool guy tell me that my old Minimax heater has brass and copper header and heater exchange, and that this ruins the plaster. This process is called bluing of the plaster. Is this true? Should I replace ASAP?

Obviously, I'm very concerned. I just re-plastered like two years ago.

P.S. This heater is even before it was Pentair branded, though I can't remember the name label at the moment.

Replace your pool guy! They have no clue what they speak of.

 

[pooldv]

If the heater has a copper heat exchanger then making sure pH stays between 7.2 and 7.8 at all times will prevent any issues. PH below 7.2 can lead to corrosion of copper over time leaching copper I to the water and cause copper staining.

Your plumbing is a little weird but it is not really a problem. High temp unions would be better but are not required.

It is amazing to me how people just say stuff with no facts or evidence to back it up. I guess they read it on the internet.

 

[tcjern]

Lol. But reading on TFP is good. I don't think that I'll be using him. I don't have a pool guy per say, as I try to do most of this myself. But since 1) I'm going with Pentair I don't want to lose the full Warrenty, and 2) I'm thinking to clean up the plumbing I'd rather have it done by a pro. Switching to the Quad requires input and output reversed.

Thanks for the advice and comments. Really appreciate it. Puts my mind at ease.

 

[pooldv]

Sounds like a good plan.