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Viessmann Re pipe need a qualified eye

Tonerlow
Tonerlow Member Posts: 60
Going to approach the plumber about re-piping our 2 yr old Viessmann into a primary/ secondary set up. A have pics attached of the current system and my rough drawing of the re-pipe. Is this configuration accurate. Can closely spaced tees take off in opposite directions or must they take off the same way (I would have them plumbed to both take of towards the camera if this was the case, hard to draw that in 2D)

Right now we have system flow via the 1/2" ball valve and this is creating turbulence and noise. Also I need to shoot some rad and pipe temps, but I think it is possible the flow is short cycling thru this bypass rather than reaching the upstairs properly. This would be due to head pressure being greater than the restriction of this bypass valve correct? 2 south facing bedrooms seems to not heat as well as the rest of the first floor. I have access to a thermal camera and plan to shoot pipe temps in the boiler room and upstairs rad piping. If I can (hopefully) prove flow issues with this data then I should have good grounds to tell the plumber it needs to be rectified at no cost.


Comments

  • STEVEusaPA
    STEVEusaPA Member Posts: 6,506
    Maybe you don't use a plumber where YOU have to tell HIM how to pipe a boiler. If only they came with manuals...
    steve
    ethicalpaulAlan (California Radiant) Forbesunclejohn
  • Tonerlow
    Tonerlow Member Posts: 60
    @STEVEusaPA Downside of living in a town of 1000 people and trying to support local. I would be fine to have a more experienced contractor fix this but don't want to be on the hook for the cost. So I am trying to reach a solution that doesn't involve going to court and can resolve this peacefully. Have found this forum to be a great resource, I am hoping if I do some legwork for him he will be more agreeable.
  • Ideally, you install a low loss header and pipe it as shown in the Viessmann instructions, but you don't have much room, so your primary-secondary plan is the next best thing.

    Also, install your expansion tank in the proper location, i.e. pump away from it.
    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
  • hot_rod
    hot_rod Member Posts: 21,865
    How much of a repipe do you want to take on? I don’t see a good air purger, a dirt/ mag sep would be a nice addition.

    How many zones, upstairs and main floor, 2?

    Here is a boiler loop, current pump, air purger, the primary loop.

    Closely spaced tees, one circ and two zone valves, Webstone purge ball valve on return at close tees

    P2 could be an ECM delta p circ to adjust to 1 or 2 zone flows is the secondary loop.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
    GGross
  • Tonerlow
    Tonerlow Member Posts: 60
    @hot_rod Air purge as viewed from left hand side. On the pics I posted it is hiding behind the gas line. 

    Tie the expansion tank in just below it and hang it above head height over the washing machine door ? 

    Also as this is a closed glycol system is it still recommended to have a dirt trap ? I raised this to the plumber as the in floor heat at work has one and he said not necessary on closed loop systems. I do know they did an acid wash on the piping on the original install.  
  • hot_rod
    hot_rod Member Posts: 21,865
    Here is what goes on inside a boiler everytime the burner kicks on. Air is driven out of solution, tiny microbubbles. Same thing you see when you heat a pan of water on a stove top.
    A good air purger has a media inside to collect and eliminate those bubbles.

    A combination device could grab air, dirt, and magnetite.

    Glycol is a tough solution to get air out of, so I'd get a microbubble type air purger in there somehow.

    Any air reduces the efficiency of the boiler and can lead to hot spots in the heat exchanger.

    The vent you show is best for getting air trapped at high points, it is not a central air purger.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
    Tonerlow