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.

Help: Blew my transformer and the 120v part of a ZVC

Options
2»

Comments

  • HomerJSmith
    HomerJSmith Member Posts: 2,469
    Options
    Ed Young, I am taken-aback by your post. Your post is amazing. The graphics and explanation must have taken a lot of time and effort on your part. You are my hero of the day.
    MikeAmannEdTheHeaterManErin Holohan Haskell
  • SENorthEast1895er
    SENorthEast1895er Member Posts: 80
    edited March 4
    Options
    @HomerJSmith

    Ok, thanks. I think using the ZVC "incorrectly", as I am, avoids the problems you've brought up (until someone else works on the system, at which point they won't understand what's going on).

    1) I'm pretty damn sure the ZVC doesn't turn on the boiler or the circ until the ZVs are open (it's been a few months, but I did a ton of testing on it). That's why I'm running all 3 wires from the ZV into the ZVC.
    2) TT will, unfortunately, will close regardless of whether it's a DHW or CH call. This is why I'm using the ZVC "incorrectly", described below.
    3) ZVC does have priority zone.

    Per someone's recommendation on here, I used the secondary zone circulator end switch (unenergized, of course) as the TT call for the DHW.

    This means that, when DHW is called, the ZVC energizes the DHW ZV, waits for it to open, and then simultaneously sends calls to CH (via TT) and DHW (via secondary-circ used as TT. The primary circ is also called; this end switch is used as intended). Obviously, the Munchkin overrides the CH call.

    Behavior is the same if both zones are calling. All I need to do is make sure the ZVC and the Munchkin have the same max-override timeout (60 minutes), which I've done.

    @EdTheHeaterMan
    As always, thanks for the thorough explanation. I read one of Dan's books; enough to have a passing familiarity with the Point of No Pressure Change (and bidirectional flow inside a single pipe). I suspected it had something to do with the Expansion tank. That expansion tank is also on the circuit that is back-flowing; maybe it's contributing to it.

    So I guess I'm stuck just bleeding for months on end until I fix the piping. Bah humbug.
  • docbar99
    docbar99 Member Posts: 31
    Options
    @SENorthEast1895er - Thank you for your suggestion- I like the idea, it may bean easier solution and it looks like that unit is not that expensive. Where would be the correct place to install that device?
    Many have suggested that the circulator should be moved to the supply side. If that is the case, would it be north of the circulator?


    Also- do these devices have to be cleaned out periodically? Does the rust in the water clog it up over time?

Categories