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

CapnDave

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.

Robert O'Brien

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.

STEVEusaPA

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.

SWEI

That system truly has it all!

CapnDave

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

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.

CapnDave

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.