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WM combi heat exchanger bad in 3 years

ChrisJ
ChrisJ Member Posts: 16,316
My sister's WM combi unit needs a heat exchanger and I think it's only 3 years old.

I'm assuming this isn't normal, is there anything typical that causes such a failure this fast that I mention to her?

Unit runs on LPG and they have well water. Unfortunately I don't know much more than this at this point.

Single pipe 392sqft system with an EG-40 rated for 325sqft and it's silent and balanced at all times.

Comments

  • hot_rod
    hot_rod Member Posts: 23,399
    Is it leaking? If so where?

    Water quality
    Inadequate flow
    Combustion not dialed in
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
    ChrisJSuperTech
  • ChrisJ
    ChrisJ Member Posts: 16,316
    edited December 2023
    hot_rod said:

    Is it leaking? If so where?

    Water quality
    Inadequate flow
    Combustion not dialed in

    I doubt it's leaking, but how do these work with domestic hot water? That's fresh water being fed into it somewhere?


    The other 3..........I wouldn't be surprised if all 3 are issues.


    EDIT : I just realized you meant is the heat exchanger leaking. I'll ask.

    Single pipe 392sqft system with an EG-40 rated for 325sqft and it's silent and balanced at all times.

  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 16,488
    edited December 2023
    If it was installed right it should last 3 years if you do nothing to it. Unless something unforeseen happened to it.
    ChrisJ
  • hot_rod
    hot_rod Member Posts: 23,399
    ChrisJ said:

    hot_rod said:

    Is it leaking? If so where?

    Water quality
    Inadequate flow
    Combustion not dialed in

    I doubt it's leaking, but how do these work with domestic hot water? That's fresh water being fed into it somewhere?


    The other 3..........I wouldn't be surprised if all 3 are issues.


    EDIT : I just realized you meant is the heat exchanger leaking. I'll ask.
    I was thinking in terms of the boiler (HX). Is it the flat plate HX for DHW that is leaking?
    Most brazed plate type, O ring connections into a composite block, one or two pinch bolt keeping it together.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
    ChrisJ
  • ChrisJ
    ChrisJ Member Posts: 16,316
    I'm told the return tube to the heat exchanger is leaking at a factory connection where's it's crimped.

    Their contractor is working with WM to try and get it replaced 

    It sounds like it's caused damage to a board as well 

    Single pipe 392sqft system with an EG-40 rated for 325sqft and it's silent and balanced at all times.

  • HomerJSmith
    HomerJSmith Member Posts: 2,635
    Have your well water tested. Well water can have a lot of minerals in it. That can plug up the heat exchanger.
    ChrisJ
  • kcopp
    kcopp Member Posts: 4,472
    Is this the Aqua balance?
    ChrisJ
  • ChrisJ
    ChrisJ Member Posts: 16,316
    kcopp said:
    Is this the Aqua balance?
    Yessir

    She just sent me this


    Single pipe 392sqft system with an EG-40 rated for 325sqft and it's silent and balanced at all times.