Combi Boiler System Installation Help

Discussion in 'Boiler Forum' started by Reicherb, Sep 4, 2021.

  1. Reicherb

    Reicherb Member

    Joined:
    Nov 7, 2013
    Location:
    Linden, MI
    I made a mistake... I have 120' of non oxygen barrier PEX in my system. The air scoop and the expansion tank are the only components that aren't copper, brass, or stainless. The pex is inside a wall now. Do I need to open the wall to replace it or will I be ok?

    Thanks.

    Edit... The circulators are cast iron as well. I'm using Glycol if that matters.
     
  2. Reicherb

    Reicherb Member

    Joined:
    Nov 7, 2013
    Location:
    Linden, MI
    What if I add a corrosion inhibitor?
     
  3. John Gayewski

    John Gayewski In the Trades

    Joined:
    Aug 7, 2021
    Location:
    Iowa
    If you add corrosion inhibitors you'll be fine. It's something that needs to be kept up and monitored that's all.
     
  4. Reicherb

    Reicherb Member

    Joined:
    Nov 7, 2013
    Location:
    Linden, MI
    Thank you
     
  5. Reicherb

    Reicherb Member

    Joined:
    Nov 7, 2013
    Location:
    Linden, MI
    I've got everything plumbed and wiring it up. I'm a bit confused. I'm using a Taco ZVC403-4

    Here is the manual for the controls:
    https://s3.amazonaws.com/s3.supplyhouse.com/product_files/Taco-ZVC403-4- Install.pdf
    It seems pretty straightforward.
    Zone valve and thermostat connections are super easy.
    System and secondary pump looks straightforward.


    How do I tell the boiler that there is a call for heat? It's more than connecting the pump to the taco control. Right?


    Here is the boiler manual. Wiring starts on page 48.
    https://s3.amazonaws.com/s3.supplyhouse.com/product_files/Weil-Mclain-383-100-030-User-Guide.pdf

    Thanks.
     
  6. Reicherb

    Reicherb Member

    Joined:
    Nov 7, 2013
    Location:
    Linden, MI
    It works!

    Thank you all very much for our help.
    IMG_20211123_211402532.jpg
     
    houptee likes this.
  7. John Gayewski

    John Gayewski In the Trades

    Joined:
    Aug 7, 2021
    Location:
    Iowa
    Looks good. Very nice. It warms my heart to see someone appreciate the value and quality of copper sweat joint vs other available (but interior) connection types.

    Are those 90's on the air supply and return kosher? I for some reason thought they wanted a certain amount of straight pipe before a 90.
     
  8. Reicherb

    Reicherb Member

    Joined:
    Nov 7, 2013
    Location:
    Linden, MI
    I hope it's all kosher! I honestly don't know. It seems to be working well.

    I do still need to adjust the max water set point and the flow rate of both circulators.
     
  9. Reicherb

    Reicherb Member

    Joined:
    Nov 7, 2013
    Location:
    Linden, MI
    The boiler has been running for a number of days. I've got a few questions. The typical setpoint is going to be 50 degree but I'll warm it to 67 on occasion.

    I'm feeding the barn with 100 degree water and it's coming back about 70 degrees. Does that seem appropriate or should I slow the circulator down?

    The primary circulator runs after there is no longer a call for heat. I assume this is to circulate the warm water. The secondary circulator is not running and all zones are closed. Any ideas how to either stop the circulator or get it to circulate it into the building?

    Every day, I find a very small amount of water (glycol actually) on the floor under the pressure relief valve. The boiler and the pressure gauge I have near the pressure relief both shows 20psi or less every time I look. Any ideas what the cause might be?

    Thanks!
     
  10. John Gayewski

    John Gayewski In the Trades

    Joined:
    Aug 7, 2021
    Location:
    Iowa
    Is that a check valve to the left of the relief?
     
  11. Reicherb

    Reicherb Member

    Joined:
    Nov 7, 2013
    Location:
    Linden, MI
    Yes. Is that the issue?
     
  12. John Gayewski

    John Gayewski In the Trades

    Joined:
    Aug 7, 2021
    Location:
    Iowa
    I'm thinking so. Hard to tell exactly from Iowa.
     
  13. Reicherb

    Reicherb Member

    Joined:
    Nov 7, 2013
    Location:
    Linden, MI
    Is there a different location it should be installed? Can I just remove it?
     
  14. Reicherb

    Reicherb Member

    Joined:
    Nov 7, 2013
    Location:
    Linden, MI
    Should I swap the location of the guage and the check valve?
     
  15. John Gayewski

    John Gayewski In the Trades

    Joined:
    Aug 7, 2021
    Location:
    Iowa
    Which way is that primary loop pumping?
     
  16. Reicherb

    Reicherb Member

    Joined:
    Nov 7, 2013
    Location:
    Linden, MI
    The right side is the return side of the boiler.
     
  17. John Gayewski

    John Gayewski In the Trades

    Joined:
    Aug 7, 2021
    Location:
    Iowa
    To me it should left of the tees
     
  18. Reicherb

    Reicherb Member

    Joined:
    Nov 7, 2013
    Location:
    Linden, MI
  19. John Gayewski

    John Gayewski In the Trades

    Joined:
    Aug 7, 2021
    Location:
    Iowa
    I'm
    Not sure. Page 34 for water piping shows it on the supply. They usually are last though. I was thinking there might be a check built into the circulator that is messing things up. Does your gauge record pressure spikes with a tattle tail needle? In your picture the condensate is in that same area also. It'd be nice to make sure that it's water expansion causing the relief to trip and not something else.
     
  20. fitter30

    fitter30 Well-Known Member

    Joined:
    Feb 2, 2020
    Occupation:
    Retired service tech
    Location:
    Peace valley missouri
    Your pressure is running 21 lbs? Why its floor heat? What air pressure is in the expansion tank cold system 100* f or less? How many gallons of water in the system and model and brand of ex tank? 30* td across boiler would like to see more flow 20* but its ok.
     
    Last edited: Dec 1, 2021 at 5:19 PM
Similar Threads: Combi Boiler
Forum Title Date
Boiler Forum New HTP Combi Boilers EFTU-199WCN vs ELU-199WCN Aug 9, 2021
Boiler Forum Switching to tankless combi-boiler May 18, 2021
Boiler Forum Understanding of a Combi Boiler Mar 1, 2021
Boiler Forum Combi Boiler: Bosch vs Dunkirk Jan 14, 2021
Boiler Forum Combi Unit vs Separate Boiler and DWH Dec 15, 2020

Share This Page