Heating Help

zone valve question

Have a taco 3 wire valve on geothermal system would like to replace with honeywell v8043
wondered if anyone had tips on the wiring to make it easy.

any response greatly appreciated.

2-wire

3-wire powers the valve open and closed. The H/W is spring closed, so now you only use 2 wires to power it open.

Other factors may be involved though such as a signal from the 3 wire must be changed to end switch operation from the 2-wire valve head.

are all 3 terminals used on the Taco?

Easy wiring. Your #1 on your taco will become TH on the H/W, #2 on the taco will become TR and jump it to the end switch terminal above it. #3 on the taco will be the other end switch terminal. The bottom far left terminal on the Honeywell is nothing, and not used. If there are only 2 wires on your Taco, the end switch will not have wires connected to it. Only TH and TR will be used, like an EK. Good luck

Taco

That is not a power open/power close valve.
With the Taco valve You aply power to two of the terminals and this opens the valve - the third wire feeds power back to the heat pump to start the compressor.
The Honeywell valve may not have enough closing force to stop the water flow.
I would replace it with another TACO.

thanks for the replies

plumbed in the hw and you were right won't close all the way. will be talking to the salesman tomorrow. and yes the taco uses all 3 wires and thanks for the how to on the wiring.

system pressure

I believe the old taco valves were a slow opening globe valve design ( heat motor ) I believe the mh valve use a spring and rubber ball device, I would check both manufacts. for pressure drop and flow data   There have been water hammer problems in the past if the wrong valve is installed.  I agree with Steve.

Thanks for the advice

Where is a good place to buy the Taco valve.

taco

most hvac supply houses should stock them  Taco is a large manufact. of valves pumps etc