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Zone valves wired backwards

I had a hot water system installed last year to replace electric heaters. The system has been more or less operating correctly this year, but it seemed two zones were turning on when one thermostat was active. The plumbing company seems to be dodging my calls (I've already had several issues such as a seized aquastat, miswired zones, reversed supply/return lines to radiators, exhaust condensing and freezing over fresh air intake), so I thought I would take a look and see if it was something simple.

While taking a look at the wiring, it seems to me the zone valves were wired backwards on all of my heating zones. The valves are Honeywell V8043E1012 zone valves, and it appears the thermostat white wire is connected to one of the yellow wires (yellow are motor connections according to the sticker), while the red wires ("end swt") are hardwired to the power and common. Am I correct in understanding the red should be connected to thermostat W and common, and the yellow to the 24Vac and common?

It seems the configurations would be functionally the same, but I'm now pumping motor current through tiny thermostat wires and whatever relay is in the thermostat. Can I get a confirmation that I'm in the right on this? How concerned should I be with the valves wired incorrectly?

Also, is it common to install some kind of terminal boards or anything for routing wires? There's currently a massive rat's nest of wires all over the place just zip tied together or tucked behind pipes, and I'm curious whether that's normal or if this really is just poor workmanship.


  • Mark Eatherton
    Mark Eatherton Member Posts: 5,840
    Doesn't sound right. Got pictures?

    Systems aren't supposed to operate "more or less correctly". They are supposed to be reliable 99% of the time. Where are you located?

    It's not so much a case of "You got what you paid for", as it is a matter of "You DIDN'T get what you DIDN'T pay for, and you're NOT going to get what you thought you were in the way of comfort". Borrowed from Heatboy.
  • skalor
    skalor Member Posts: 13
    Generally the thermostats are controlling the motor side of the zone valve and the end switches are hooked to the TT contacts on the boiler. There are other ways to wire them using zone valve controllers but sounds like you may just have a two zones cross wired to run at the same time. Zone valves are pretty low wattage, <10, so there is hardly any amperage on the thermostat wire.
  • NY_Rob
    NY_Rob Member Posts: 1,370
    Sounds like your t-stats and zone valves should be wired like this...
  • bdboiler
    bdboiler Member Posts: 2
    Thanks for the responses, sounds like the wiring is correct and I was mistaken. I was expecting the switch wires to be the thermostat connections, but now I understand they are intended to signal the valve opening to the boiler and the thermostats are correctly driving the motor.

    Mark: thanks for the concern, though the system has been fairly reliable other than hiccups which I've come to expect with new installations of anything (knock on wood).