MasterTemp Unions

Hydrochloric acid can be used, but use a very dilute solution.

Hydrochloric acid does not oxidize copper, but it does strip off the protective patina layer, which makes the copper susceptible to oxidation until the copper patina reforms.

All descalers will probably dissolve the protective patina layer, so you need to be extra careful with the chemistry after descaling.

Keep the pH up and keep the FC as low as possible without risking algae.

It might take about 2 weeks to reform a patina on the copper.
 
Hydrochloric acid can be used, but use a very dilute solution.

Hydrochloric acid does not oxidize copper, but it does strip off the protective patina layer, which makes the copper susceptible to oxidation until the copper patina reforms.

All descalers will probably dissolve the protective patina layer, so you need to be extra careful with the chemistry after descaling.

Keep the pH up and keep the FC as low as possible without risking algae.

It might take about 2 weeks to reform a patina on the copper.
I was planning on doing this after I closed the pool for the season and had everything drained. I was going to run fresh water through it to flush out the descaling solution, but hen leave it dry until spring. Would that be OK, or should I wait until I open in the spring?
 
How did you determine that the heater was scaled?
So i have been battling a positive CSI all summer. I have high TA fill water and surprisingly stubborn PH that does not want to rise despite aeration. This makes controlling my CSI difficult and I did not have great success this summer. My SWG showed some signs of scale, so I wanted to descale my heater as well, more as a preventive measure. I also get some popping/rattling sometimes when we fire it up.
 
Descaling is aggressive to equipment and it should only be done if necessary.

You can check the stack flue temperature to see if it is high.

If it is too high, descaling might help.

You can remove the manifold to check the heat exchanger if you want to be sure before descaling.

Get new O-rings before removing the manifold.
 

Exhaust Gas Temperature.​

While running, press and hold the On button to display the exhaust temperature (Older Models).

The new models use the Menu to get the SFS.

Here is what the normal exhaust temperature should be:

  • Below 250 degrees...very low
  • 250 to 290 ..................low
  • 290 to 350.................acceptable
  • 350 to 480 ..................high
  • Above 480...................error/shutdown.
Note: HD models can be up to 75 degrees higher.

HD models use a cupro-nickel heat exchanger and the efficiency is slightly lower (82% vs. 84% for a copper heat exchanger) resulting in less heat transfer and more waste heat.

The extra 2% waste heat causes the exhaust gas to be hotter.

If the exhaust gas temperature is higher then normal then water may be bypassing the heat exchanger through a broken bypass valve or the heat exchanger might be scaled or sooted.

If you hold down the "pool on" button, it stays on 80, then flashes to 40, then back to 80, then the 80/40 reading and E05 indicate that the board is not getting a reading from the sensor. It's usually a bad sensor or damaged wires.

 
If you unscrew the connector tubes, I would want to have two new U9-226 O-Rings (Part #13) to replace the old O-rings if necessary.

I am not 100% that the thread is 2" NPT, so verify as needed.
It’s straight thread and there’s an o-ring inside like a compression fitting.

I’ve cracked 2 headers trying to get an NPT nipple to thread into it without leaking…it just goes to show you I was dumb enough to try twice 😂

NPT will thread right in until the taper limits it and it’ll leak under pressure even with an o-ring. I was never able to find a 2” NST PVC fitting. I even considered a 2” die but decided using the pentair unions was probably a better idea.
 
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It’s straight thread and there’s an o-ring inside like a compression fitting.

I’ve cracked 2 headers trying to get an NPT nipple to thread into it without leaking…it just goes to show you I was dumb enough to try twice 😂
Will these work?

1697553317804-png.536124
 

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Will these work?

1697553317804-png.536124
Those are NPT so I doubt it. The edge of the header inlet/outlet is very thin and sharp so I don’t think that O-ring would seal against it without popping off or getting cut…But I’d like to try😂

I don’t understand why Pentair uses those extensions instead of just using NPT and unions directly on the header?
 
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It looks like the actual Pentair unions will probably be my best bet. I was just hoping to avoid the proprietary fittings and paying the 'Pentair Tax'. But that's what it costs to play sometimes.
 
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Sometimes it’s a manufacturing issue. Molding those plastic headers takes quite a bit of engineering to figure out how to design the molds with sprues to allow for a defect free product as well heat dissipation, shrinkages, etc. It’s easy to think that you just cast whatever the final shape is and it works, but it’s a lot more complicated than that with a good bit of trial and error involved. So at then end of the day they may have had to make the casting mold with the shorter inlet/outlet ports so that it came out in the right shape defect free and then they just got the right length by putting a thread on it and adding the extension.

Another possibility is that the header block is used across a couple of different products where some don’t need the longer inlet/outlet extensions. So to avoid the unnecessary costs of having two different header block designs, it was cheaper to just make one universal design and then modify it for a particular product line.

There’s all sorts of compromises that have to be made in product engineering that look weird to the end user but makes sense in the larger picture.
 
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