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2 Thermostat- 2 zone valve wiring

in Gas Heating
Hi folks. Posting a image of my 2 thermostat, 2 zone valve (taco) wiring. I have one open (unconnected) wire from thermostat 2 sheath (brown)
Can anybody tell me where that should connect. Thanks, Forrest

Can anybody tell me where that should connect. Thanks, Forrest

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Comments
PHC News Columnist
Minnich Hydronic Consulting & Design, LLC
https://heatinghelp.com/find-a-contractor/detail/minnich-hydronic-consulting-and-design
Under this 2 wires stick out (I'm going to guess these go to "T" terminals on boiler) see pic
++++++++
So the red wires from the 2 thermostats go to the transformer, which post?
Sorry, I'm dizzy
bill: would you say the brass is on the left in the photo? If so what leads go to it?
Those 2 wires that I am assuming go thru the conduit to the T-boiler connections are just red and white, do I assume red is always positive?
Thanks.
Take it one step at a time.
1. One side of the 24 volt side of the transformer.. call it the "hot" side feeds 1 terminal (R) on each of your two thermostats
2. the "neutral or common" side of the transformer feeds terminal #2 on both zone valves and goes to one of the TT terminals on the boiler.
3. connect both terminal #3s from the zone valves together and also connect terminal #3 to the other TT terminal.
4. Connect terminal #1 on the zone valve to the other thermostat terminal. (for it's respective valve)
5. Done
Hot comes from the transformer to the thermostat. When the stat make on a call for heat it powers the zone valve terminal 1.
terminal 1 makes contact with terminal 3 inside the zone valve through an auxiliary end switch contact to power the boiler terminal T. The neutral side of the transformer powers terminal #2 on the zone valves and the other boiler t terminal
If I follow you, then my illustration seems correct, except for the thermostat 2 . Should both red wires coming from the thermostats go to the connection on the right (as thermostat #1 is in the illustration)?
My voltmeter isn't much help.
Take the red wire off from t-t boiler to transformer and make it come from the #2's on the zone valve to t-t boiler
I just touched the wire to the trans and saw a light spark, and wonder if this is ok. (don't want to blow the transformer)
Thanks
The other terminal of the transformer should be connected to terminal 2 of both zone valves and to one of the T-T terminals on the boiler.
The green wire you show from terminal 3 of both zone valves connecting to the other T-T terminal on the boiler is the only one which is correct.
Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England.
Hoffman Equipped System (all original except boiler), Weil-Mclain 580, 2.75 gph Carlin, Vapourstat 0.5 -- 6.0 ounces per square inch
Sorry about the delay, work/Thanksgiving and all, hope you are all having a good Holiday.
So here is what I have done: Both reds from thermostats now connected to transformer, right post. Green is now connected to zone valve 1. SEE NEW ILLUSTRATION
My questions now;
1. is the "TT" connection correct.
2. Because I assuming the red of the thermostat was connected to the correct side of the transformer (right post) how do I conform this (both are now connected to the right side)
3. Note: What I am fixing was what was in place, this is not a new instalation, It was so messy, wires dangling, taped to hot water pipes, twisted extensions etc that I wanted to clean it up, in the process I came upon the problems.
4. Thanks again, great help here!
and the other TT connection is from the transformer terminal that connects the #2s on the zone valve
Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England.
Hoffman Equipped System (all original except boiler), Weil-Mclain 580, 2.75 gph Carlin, Vapourstat 0.5 -- 6.0 ounces per square inch
Jamie: At this point thermostat 1 + 2 are wire leads that I haven't a clue which thermostat they go to upstairs, just hang from the ceiling. But I think this should be correct as one of the two's wiring has remained the same. So I would say that my labeling was incorrect, and your point makes sense.
Next will be to see if it works.
I did a thread in the spring where I did a lot of work to this system, swapping out the circulator pump, back flow, etc. I may need to visit that next.
Thanks a lot, Happy Thanksgiving.
A proper meter and knowing how to use it will help you troubleshoot your problems. Please don't touch wires together to look for a 'spark'. Also, give your motor in your zone valve enough time to close the end switch before rapidly turning things on and off.
No it is not working, the circulator pump comes on only.
Sometimes, the best advice I can offer is to put the tools down and hire a pro to do it.
PHC News Columnist
Minnich Hydronic Consulting & Design, LLC
https://heatinghelp.com/find-a-contractor/detail/minnich-hydronic-consulting-and-design
But while you have all the wires off and the power off do some testing, maybe you broke a wire along the way. This is why I asked if you had a meter. Here's some things to try:
1. Turn the thermostat up for a call for heat. Go down to the basement, set your meter for continuity, and clip it on to the two t'stat wires. If you have continuity then the wires to the thermostat and the thermostat are working.
2. Power off, check continuity of all low voltage wires by twisting a pair together at one end, puttin your leads on the other end (same 2 wires loose)
3. Nothing wired, turn on power, set meter to volts, check both terminals of transformer, should have 24V.
4. Power off, wire as per @Stephen Minnich diagram.
5. Power on, turn up one thermostat, see which zone head has 24v at terminals 1 & 2.
6. Give it a minute for the end switch to close, when it does, you'll here the circulator come on and maybe the burner will fire-depending on aquastat settings/water temp. If it doesnt work, check for continuity at 2 & 3. If continuity, check for continuity at x-x on the boiler. If continuity, aquastat is bad.
7. Turn down thermostat, power off, connect the other zone, repeat 1-6.
If the zone head isnt getting 24v, and the wiring is good and correct, zone head is bad.
If the zone head is getting 24v, and the end switch (2&3) isnt making (closing), the zone head is bad.
2. continuity
3. I have 29 volts
4. As far as I can tell my wiring is just like Steve's. Steve's diagram fails to show which side of the transformer is plus and which is neutral.
5. zone valve 1 is 2nd floor as I expected
6. As soon as turn on the power the circulator pump comes on. I had continuity at 2+3. And with power on also had continuity at TT on the the boiler circuit board (if that is where you meant)
7. so I stopped there.
Now I had a "Plumber" check out the setup. I had replaced the Taco Hy-Vent (and much more) which water was coming out of when I was filling the system, so I called in the "plumber" who put a new Hy-Vent, apparently the one I bought was defective. The system started up and he bleed the system and it seemed to be working. But he honestly had an "lackluster" attitude and left. So I went to start it about a week later and it was in the same condition it is now. And that is that as soon as you turn on the power the circulator pump starts and the boiler does not fire. Re-doing and cleaning up the wiring was in hopes of solving the problem as it was a mess.
Thanks
First off, there is no plus or minus on the transformer -- it's AC. One terminal (and for most transformers it doesn't matter which) will be called C, or "common". The other is R or hot.
Now. If your wiring is as you showed it in the sketch I commented on above, do the following:
For the following, note that one probe of the multimeter will always be on the C terminal of the transformer -- get a helper and a longer probe if you need it.
1. Both thermostats off. Check the voltage at all three terminals of both zone valves. All voltages should be zero (or very very small).
2. Turn a thermostat on. Check the voltage at all three terminals of the corresponding zone valve. Terminal 1 should be about 24 volts. Terminal 2 should be zero. Terminal 3 should be about 24 volts, after the zone valve has opened (this may take a bit -- patience).
3. Turn that thermostat off and the other one on. Check the voltages as in 2. above.
4. Leave one of the thermostats on. Check the voltages at the T-T terminals. One should be zero and the other should be about 24 volts. Note and mark which of the T-T terminals reads zero.
Now. Go back and do exactly the same thing, only with the probe which was attached to the transformer attached to the T-T terminal which read zero before.
If all of the above checks out, the wiring is almost certainly OK so far as the zone valves, thermostats, and T-T terminals are concerned. Otherwise, you have a problem either in the wiring (loose connection, open wire, misidentified wire...).
Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England.
Hoffman Equipped System (all original except boiler), Weil-Mclain 580, 2.75 gph Carlin, Vapourstat 0.5 -- 6.0 ounces per square inch
Thanks
Here is a new pic
1. I read 29-25 volts at zone valve 1 on terminal #1. All other terminals were 0. So i'm guessing this should be rectified before going on.
Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England.
Hoffman Equipped System (all original except boiler), Weil-Mclain 580, 2.75 gph Carlin, Vapourstat 0.5 -- 6.0 ounces per square inch
Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England.
Hoffman Equipped System (all original except boiler), Weil-Mclain 580, 2.75 gph Carlin, Vapourstat 0.5 -- 6.0 ounces per square inch
Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England.
Hoffman Equipped System (all original except boiler), Weil-Mclain 580, 2.75 gph Carlin, Vapourstat 0.5 -- 6.0 ounces per square inch
question.
On the Aquistat board: 1 connection is labeled "TV" the other is labeled "T". Can someone tell me which one of these gets positive and which gets common? Or does it matter?
The transformer seems to be the most confusing part, everything makes sense to me and wiring seems to check good. In my system the transformer is constantly on and does not switch off with the main switch.
Thanks
Still no answer to my transformer connection at the aquastat.
Thanks for the support