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Need to ID TT terminals on multizone controller for electronic zone valves

I have a gas powered 3 zone hydronic baseboard system with a Honeywell R8335A controller and am replacing the gravity flo valves with Taco electronic zone valves. These valves have a capacitor to close valve which charges from the TT terminals (end switch). I cannot identify where to land these wires. Any help would be appreciated. Attached is a pdf for the zone valve and a jpg of the controller.

Comments

  • Robert O'Brien
    Robert O'Brien Member Posts: 3,385
    Those zone valves have been discontinued for good reason. You are going to have a pump and zone valve on each zone? Waste of time but if you persist, you need a transformer to power the zone valves. The thermostat will open the valve and the end switch will turn on the pump.
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  • STEVEusaPA
    STEVEusaPA Member Posts: 5,304
    Here's a photo of a system like yours in action. Relays, contactors, zone valves for check valves and circs....oh my!
    Warning! Do not view this on a full stomach.
    steve
    SWEI
  • SWEI
    SWEI Member Posts: 7,356
    That system truly has it all!
  • CapnDave
    CapnDave Member Posts: 3
    Thanks for your comments. My luck the valves were discontinued! I thought some sort of zone valve was necessary (eg gravity flo valves were spec'd at install) to prevent unintentional convection heating in zones not calling.
  • STEVEusaPA
    STEVEusaPA Member Posts: 5,304
    You could just use the flow checks specified (what was wrong with them?) or use circulators with flow checks installed. They even make shut-offs with circulator flanges that have a flow check built in.
    steve
  • CapnDave
    CapnDave Member Posts: 3
    Thanks for the info. Old gravity flo valves were leaking and corroded. I need to replace one of the 30 yr old circulators and will look into the built in flow checks.