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Zone valves are in series, not parallel

I'm very much a non-expert, so excuse my naive questions. One of our two radiant floor heating zones wasn't coming on. I watched youtube videos to learn how to service the system and eventually ended up replacing one of the power heads on one of the two zone valves, so, immediate problem solved, we have heat in both zones!

However, in looking over the system, it looks like it is set up so that valve 2 (the one I fixed) is wired in series with valve 1. So, valve 2 can only open when valve 1 is open. This isn't very good in general, but it's worse because valve 2 controls the colder north side of the house and that area is often chilly, even when the valve 1 zone is really toasty.

I'm thinking of 2 solutions: First, reverse the logic and set it up so that valve 1 is "downstream" from valve 2, the opposite of the way it is now. Or, second, wire the two valves in parallel so they can turn on fully independently. For the life of me, I cannot understand why it wasn't set up in parallel to begin with. (the house is 1990's vintage construction and we've only been here 3 years).

So: (1) would reversing the order of the valves in a series system be okay? (2) is there any fundamental reason not to have the two valves/zones working in parallel? I can't see why there would be, but then, why was it ever set up in series to begin with?

Thanks for any help!


  • Jamie Hall
    Jamie Hall Member Posts: 18,923
    Can you draw a sketch of how the thing is piped, and where the valves are?
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
    EBEBRATT-Ed Member Posts: 11,989

    A few pictures would help. What you describe dosen't sound right
    HVACNUT Member Posts: 4,590
    24v A/C valve heads wired in series wouldn't even work without a relay somewhere in the circuit or the end switch on #1 is providing 24v to power the #2 valve. But why?
    What brand actuator? 2 wire or 4?