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Non O2 bariier tubing and Lochinvar Knight

digger_2 Member Posts: 39
I am considering a new mod con boiler .Our regional Lochinvar rep said he believes there is no reason that the Lochinvar Knight would not fare well connected to this tubing. Still scares me. This boiler has only been around about 4 yrs. Thoughts?


  • eluv8
    eluv8 Member Posts: 174
    knight and non o2 piping

    The knight ships with black fittings that would have to be changed to brass, along with any other items in the system that could react with air. I would also be sure to put in some sort of anti bacterial to help keep the system from growing things. Additionally you could probably say goodbye to the warranty unless you have something in writing. Lochinvar makes a decent product, its not my favorite. Choose a boiler that has good local support and parts availability for your area just in case you need them.
  • paul_79
    paul_79 Member Posts: 91
    knight boiler

    I installed  knight on a old poly system 2 and half years ago.  The old system would eat a hole in an expansion tank in less than a year.  I put all bronze pumps and  a enamel lined expansion tank in the new system with the knight. no steel or iron at all , Plus i put in a corrosion inhibiter  and check it when i do the yearly service.  no problems so far.  The other option was to put in a flatplate heat exchanger set up / or a taco x-block ( if the btu fits the x-block 70k btu i think) 

    The lochinvar knight has been has been a great boiler. I have only installed 6 so far in the last four years but so far no problems.
  • digger_2
    digger_2 Member Posts: 39
    why I asked the rep

    Plan A for this install was to isolate the boiler and indirect DWH with a heat exchanger. However, with a heat load of only 36K btu I was trying to do it with the 50K btu boiler. mainly for it's 10K btu low fire. I have been circulating 9 gpm of 105*F or lower into a poured therma floor underlayment. A 50 gal / 42K btu output water heater has worked fine in colder weather but not in milder.

    Some have suggested that efficiency would be lost in this transition. Except for the extra pump and head loss, I don't fully understand why or how much, but it does make sense.
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