Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

No flow at manifold

joe910
joe910 Member Posts: 4
I have a US boilers K2 135 combi ran on propane, I was having an issue with the pop off valve on the central heat loop popping off every time I used The domestic hot water,Tech support Told me to tie the supply and return together That helped the pop off pressure problem. Now the system will not circulate water through the floor heat manifold. It seems as if it is just circulating around the header and boiler I’m at a loss With what the problem could be.

Comments

  • Can you take a few close-up pictures of your primary-secondary connections under the boiler?

    Have you purged all your loops of air?
    8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour

    Two btu per sq ft for degree difference for a slab
  • Zman
    Zman Member Posts: 7,611
    We need to able to see exactly how it is piped in order to help. Close up pics or a drawing would help.

    I couldn't help but notice your water filtration system appears to be piped directly to your sewer piping. If this is the case it should be remedied immediately.
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • Ironman
    Ironman Member Posts: 7,556
    It's difficult to follow the piping from your pic; however, it appears that the primary/secondary piping is not correct.

    You may also not have your pumps properly programmed in the boiler control.

    Better pics would be helpful.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • JUGHNE
    JUGHNE Member Posts: 11,279
    Is there only one pump outside of the boiler...how about inside?
  • joe910
    joe910 Member Posts: 4
    Thanks for the responses, yes there is a pump on the inside. I don’t understand the primary and secondary piping, I thought if I tied the return & the supply together with 2 close tee’s it would help my pressure problem witch it did, what exactly do I need to do to make my set up work correctly?
  • Ironman
    Ironman Member Posts: 7,556
    edited October 2020
    It has to be like this:

    From the I/O manual:


    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • Ironman
    Ironman Member Posts: 7,556
    Where's your relief valve for the hydronic side?
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • Zman
    Zman Member Posts: 7,611
    I don't say this very often but, I think you need to get someone qualified in there to straighten this out before something bad happens.
    • Your boiler is not piped per instructions so there goes the warrantee.
    • You are pumping into you expansion tank rather than away which is probably causing pressure issues including an air lock.
    • Those braided hoses are constipating flow to the zones.
    • The whole thing looks like it was constructed using whatever the local hardware store happened to have on the shelf.
    • The water filter backflush piped directly to sewer is going to allow sewage into the domestic water.
    • Who knows what else is going on, how is the boiler vented? Is it per instructions and pressure tested?
    • Was the boiler properly set up with a combustion analyzer
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • joe910
    joe910 Member Posts: 4
    Up on top
  • joe910
    joe910 Member Posts: 4
    Ok thanks, filters drain outside, & Venturi was set with combustion Analyzer