Zone valve wiring

Old 10-10-04, 12:35 PM
Visiting Guest
Posts: n/a
Zone valve wiring

In as much as I hate to ask 2nd question in as many days, your help would again be greatly appreciated.

Victim: 200yr old house - 2 loop hydronic (weil-mclain boiler) - one 2 wire thermostat (no zones)

Solution: I've been replacing the baseboards, R&R new piping, and going to install 2 zone valves (1st & second floor) to help with trying to control the heat problem; hot upstairs, cool downstairs.

I have 2 Honeywell V8043 E1012 zone valves (4 wires = 2Y/2R)
I have 2 Honeywell CT8775a thermostats (2 wire - compat. w/h.w. zone valves)
picture of control box - if needed - - top right is where existing therm. connects.

Question: How are the zone valves wired along with the 2 thermostats to the existing system. I'm removing the old thermostat.

Old 10-10-04, 03:17 PM
Visiting Guest
Posts: n/a
Angry hot water boiler wiring

in trouble. have a slant fin boiler with two honywell zone valves plus an indirect fired water tsnk running on its own circulator. redoing my basement and lost the schematic of the wiring. need lots of help.
Old 10-10-04, 04:49 PM
KField's Avatar
Join Date: Dec 2002
Location: Easton, PA
Posts: 3,015
Upvotes: 0
Received 0 Upvotes on 0 Posts
You will need a 24 volt 40 va transformer wired into ther boiler power circuit. Then one yellow wire from each zone valve will go to one of the transformer terminals. One side of both thermostats will go to the other transformer terminal. Each thermostat will then have its remaining wire go to the other yellow wire on the corresponding zone valve. One red wire from each zone valve gets tied together and they goes down to the T terminals in the aquastat where your existing thermostat is now connected. Hope this is clear enough.

Old 10-10-04, 06:05 PM
Visiting Guest
Posts: n/a
I'm a bit vague on the red wires...

One red wire from each zone valve get tied together? and the other two red wires go down to the terminals on the aquastat?


Last edited by Shiprekd; 10-11-04 at 02:53 PM.

Thread Tools
Search this Thread
Ask a Question
Question Title:
Your question will be posted in: