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Vito Tight!

Paul Pollets
Paul Pollets Member Posts: 3,656
This job had non-barrier tubing connected to a Munchkin 140 with iron pumps 10 years ago. The corrosion ate through the manifolds and shorted the telestats. Installed a new Vitodens WB2B 200-35 boiler and connected to the existing 80g indirect tank. Instead of a low loss header (which is steel, and corrodes), we connected a flat plate heat exchanger with 1" tappings between the boiler and system. The FPHX is oversized so primary flow can be achieved without "choking" the flow rate within the boiler HX. A stainless steel Grundfos Alpha runs the radiant loads. The manifolds were replaced with Uponor EP manifolds with adjustable flowports and telestats.

The closet was damn near impossible to shoehorn all of the components in.

The piping will be insulated after boiler inspection tomorrow.


  • Mpj
    Mpj Member Posts: 109

    Nice job!!

    Can I ask what the white pipe is for the expansion tank?
  • Paul Pollets
    Paul Pollets Member Posts: 3,656
    edited August 2013

    It's a SS expansion tank bracket, made for potable connections. The steel bracket ( the red one) would have corroded on the system side of the FPHX.
  • Mpj
    Mpj Member Posts: 109

    Very cool. Where did you get it from?
  • Paul Pollets
    Paul Pollets Member Posts: 3,656

    Ferguson or Consolidated Supply in Seattle. They save a lot of space and make the installation look good!
  • JStar
    JStar Member Posts: 2,752

    Job looks great. And a big kudos for catching the problem. Most contractors would just cut and slide in a new boiler without ever realizing what caused the problem.
  • Paul Pollets
    Paul Pollets Member Posts: 3,656
    edited August 2013
    #3 Boiler

    This was the 3rd boiler since the radiant renovation 15 years ago. A reputable local company who had installed the Munchkin also missed it.

    It's the first thing I look for when radiant tubing is present.

    This is a very large problem in Seattle/King County. So many heating jobs were done without barrier PEX. The rooster does eventually return to the coop and crows....
  • Zman
    Zman Member Posts: 7,542
    Nice work


    First off, very nice work.

    Do you always do your non-barrier jobs with the exchanger? We have done them the way you have and they work well. The down side is that you have more components and slightly higher boiler temps. The up is that the boiler is completely isolated from the debris left in the system by the previous boilers corroding.

    The last one we used a TT Prestige and changed all the circs to stainless. We also did a magnetic dirt seperator to remove the debris. It seems to be running well and the water has cleaned up nicely.

    Again, fine work and a solid design.

    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • Paul Pollets
    Paul Pollets Member Posts: 3,656

    Thanks, Carl. All boilers need a primary pump and the secondary pump from the FPHX is a SS Alpha. Yes, the FPHX requires extra and pricey components but only the NTI TFT boiler can be directly connected to a non-barrier system with SS pumps, without voiding the boiler warranty (to my knowledge). I can also set the curve for 2 different temps, if I needed them. This system has 1 curve for the FPHX and the DHWTank. I like the Viessmann controls, which give a lot of options for set-up.
This discussion has been closed.