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Knocking... Sometimes...

Javelin Member Posts: 138
Heating Pros,

Back in October, had a new Triangle Tube Prestige put in and it's great, but recently (since it has actually become colder out) not sure if it matters, I get a pretty regular knocking. Also installed a TT indirect tank, and the odd thing is that if I manually put on the DHW pump, the knocking goes away.. otherwise when the DHW pump it off, the knocking/rattling is there and is enough that it travels throughout the pipes throughout the house.

I've bled all the radiators - no more air coming out, and the system has (what I think to be) a properly installed spirovent that should eliminate any air bubbles I would think. Just odd that it only is silent when the DHW pump is ON, and like I said, wasn't a problem a month ago.

Does anyone have any thoughts? All the radiators DO seem to be getting plenty hot as needed and the house is toasty - just a bit noise. I've attached a couple pictures of the setup and a video with the noise is available at:

<a href="https://www.icloud.com/photostream/#A25oqs3qorqf9">https://www.icloud.com/photostream/#A25oqs3qorqf9</a>


  • RobG
    RobG Member Posts: 1,850
    Check valve

    It sounds like the check valve is chattering. It is a swing check and should be a spring check. You are also missing a spring check on the boiler return line. Call you installer and have him fix those check valves and you should be okay.

  • Javelin
    Javelin Member Posts: 138

    Thank you Rob G! I'll replace the "swing" with a "spring". The system does have a check valve on the return already, but it's just out of the photo to the left.

    Thanks again,

  • Steve Whitbeck
    Steve Whitbeck Member Posts: 669
    check valve

    There needs to be a check valve on the boiler loop going to the house system and one on the loo going to the indirect water heater.
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