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Piping Issues w/pics

Dana_9 Member Posts: 4

I'm moving forward w/a boiler retrofit. It's (3) baseboard zones and (1) in-floor zone. Last heating season, I used the in-floor zone and it performed well. I am now adding (1) bedroom baseboard zone and am having some issues. There is a primary pump that runs when the boiler fires and the zone circulators are controlled by the room t-stat. (thru a 4 zone Taco switching relay)

When the in-floor zone circ runs, it circulates thru the in-floor tubing AND the bedroom baseboard zone.

I'm thinking it might be the position of the mixing valve. I've attached pic's (be gentle) however, not able to edit or point out items well so:

The far left circ is the in-floor zone.

The circ to the right of that is the bdrm b'bd zone.

The other (2) are future B'bd zones.

The primary pump is not to visible but it is on the far right.

Sorry to ramble but your input is appreciated.

<a href="http://s625.photobucket.com/albums/tt332/danaelk/?action=view&current=COOLIO003.jpg">[u][color=#800080]http://s625.photobucket.com/albums/tt332/danaelk/?action=view&current=COOLIO003.jpg[/color][/u]</a>


  • Paul Pollets
    Paul Pollets Member Posts: 3,656
    Piping errors

    The piping for the thermostatic mixing valve is incorrect. You have major errors! The high temp pump to the B/B does not go through the mixing valve. The radiant floor does.  The mixing valve has specific instructions, and the pump attaches to the outlet or mixed temp of the thermostatic valve. I'd advise a thermometer 6-12" downstream of the pump outlet to tell you what the setpoint is.

    The header seems to be the same size as the pumping zones...I'd advise making it larger.  Get yourself a copy of Pumping Away by Dan Holohan or Modern Hydronics by John Siegenthaler for correct piping schematics. 
  • Dana_9
    Dana_9 Member Posts: 4
    Piping Issues w/pics

    Thanks for the reply, the BB zone is ahead of the mixing valve however, I've come to the conclusion that the mixing valve is installed incorrectly. I need to take it out of the 1" "header" and put it above the header and behind the circ. My thoughts are that the mixing valve creates enough resistance that the boiler supply water short circuits to the BB zone.

    Does this make sense?  
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