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Reducing ph

George_10 Member Posts: 580
Do you have aluminum in your system? i.e. the boiler or whatever?

High pH is normally not harmful to cast iron etc. But it can be extremely damaging to aluminum.

Also what other items are out of tolerence, like the fluid color, fill water pH and evidence of scale or corrosion.

The system chemistry can be addressed, but there are a few questions that need to be answered first.


  • Jon Slater
    Jon Slater Member Posts: 4
    reducing ph

    I recently had a new boiler installed and the ph is very high. What is typcally used to bring it down. Can I use muratic acid? I have a 12 gallon boiler so I dont expect it will take much. Thanks
  • Firedragon_4
    Firedragon_4 Member Posts: 1,436
    Okay, here's my rules:

    water is acidic, treat with baking soda, water is alkaline, treat with vinegar. There's a lot of others that work well too and this always helps:
  • Jon Slater
    Jon Slater Member Posts: 4
    more detail

    The ph is high off the chart on a hot tub test strip. No where near 8.5 to 11 range. I have a weil mclain cast iron boiler. The water is clear but primes and surges. I have skimmed three times and may have to continue cleaning as a I believe I have some residual boiler seal chemical from old boiler being scoured out of the system (seal chemical may be high ph?)periodically making its way back to the boiler. City supply water is high ph. The take offs might be undersized as they have been bushed down. However, before I address that I want to make sure the ph is not lending to the surging. The system is a moline vapor vacum set up on very low pressure. I'm sure I have wet steam. Thanks for your help.

  • hr
    hr Member Posts: 6,106
    Be nice to check it

    with an actual ph meter to see exactly where you stand. Not sure I would trust the strips.

    I wonder how you would get water over PH 11? Even after a TSP bath you end up in the 10-11 range. Hard to believe you fill water could be higher than that?

    Ph meters (digital)can be had for around 60 bucks. Test the boiler water and the fill water.

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  • John Shea
    John Shea Member Posts: 247
    High pH

    I recently had to drain a lot of steam system water as the result of a clogged wet return. To care for the fresh water, SQUICK was used, and then Rust Raider to prevent rust/corrosion.

    After obtaining clear water, I was getting a lot of priming of the water. Checked the pH and it was well above 11.

    I added about 2 cups of vinegar to the system, and immediately the priming stopped and the water level settled.
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