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Lochinvar Knight, calcium chunks in heat exchanger

SpeyFitter Member Posts: 422
I have a Lochinvar Knight boiler installed @ a apt. complex. The boiler circ. pump went out the other day and caused it to over temp. creating a rattle, banging, and flashing. Once the pump was replaced and flow switch fixed I noticed vibrations and a 'tinging' sounds in the lines. Took the pumps apart and found calcium chunks stuck in them. Tried to flush out but can not get them all out. Was told to flush system out with acid. Called Lochinvar to get recommendations............. nothing of course. They said to flush it out, but not what to use. Didn't want to void there own warranty. Any suggestions?

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    PLUMBARIS Member Posts: 22
    Knight Dance

    I had this happen to 1 of my installs about a year ago boiler had been in service about 14 months. We had a couple of boiler drains arranged so we could pump mild muratic acig thru it over and over for about an hour. Think I used 1acid to 4 water or 20% solution.She almost danced across the floor before we got it shut down.The only reason icould come up with was we filled the system before the softener was installed, we don't do that anymore and do put a set of boiler drains for flushing purpose.
  • Perry_5
    Perry_5 Member Posts: 141
    What warranty coverage?

    I just happened to be reading the Knight Warranty:

    "1. This limited warranty does not cover leakage or other
    malfunction caused by:

    a. Defective installation....

    b. Adverse local conditions and specifically, sediment or
    lime precipitate in the tubes and/or headers or corrosive
    elements in the atmosphere.

    c. Misuse...."


    The lime you are seeing plated out in the boiler tubes (that is where it plates out becasue they are hot). In fact - unless you use Demineralized water or extremely soft water in a spotless clean system - that does not degrade - you will get lime or sediment deposits plating out on the boiler tubes.

    Thus, as I read it - just normal operating boiler physics voids the warranty.

    Isn't it nice to know that any corrosive elements caused by anything in the atmosphere also voids the warranty as well... That takes care of ordinary dust and fine dirt that gets into the SS HX as well.

    Call me a pessimist if you will...., and maybe they will replace a few. But what warranty? Especially if a number of them start failing expect photographs of the normal deposit layer on the inside of the tubes with the rejection of your warranty claim.

    I also note that my Viessmann warranty only excludes "unusual deposits within the waterside." Unfortunately, Viessmann does also exclude most general forms of corrosion and air contaminants as well. But at least they acknowledge that there are normal waterside deposits - and that they do not affect the warranty.

  • J.C.A._3
    J.C.A._3 Member Posts: 2,981
    JMHO, But

    What flavor IS that cool-aid? Chris
  • hot_rod
    hot_rod Member Posts: 22,271
    those boilers don't ship with lime, or calcium in the HX :0

    it had to come from SOMEWHERE?

    How hard is the fill water? How many gallons in the system? Are you sure it is not taking on small amounts of fill water?

    If in fact the job site water is extremely hard, you could haul water to fill with. I bought DM water locally for 12 cents a gallon, haul it in 30 gallon plastic drums. You could blend some DM water with the site water if it is not over the top hard.

    Another option is a boiler inhibitor product, like Rhomar and others. They have a component blended in to "lock up" hardness and prevent it from plating the HX surfaces. To a point!

    But testing the fill water with a simple Hach hardness test kit would shed a lot more light on the question.

    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
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