1 out of 3 zones is not working there is no heat for that zone

desiraelynn07

We don't hear anything start up in the 2 rooms or hallway. I have outlined the value in yellow to show which one is not working. We replaced the thermostat and the taco value replacement top. And still nothing. I attached some pictures not sure if there's air in the pipe I don't understand
Also around June of this year a pipe in our kitchen had started leaking so we had to shut the main water off to the whole house. Not sure if that could of affected anything.

Jamie Hall

Turning off the water to the house while you worked on the leak shouldn't have affected anything, provided you didn't drain the heating system at the same time.

However, before you get too far down rabbit holes, check to make sure that the thermostat is really telling the valve to open. There should be two wires (maybe more, but two that count) on the thermostat, probably labelled R and W. If you take those two wires off the thermostat and put them together temporarily (remember which wire goes to which terminal -- it makes a difference sometimes) what happens? Does the zone get heat? If it does, then the problem is in the thermostat. If nothing happens, then the problem could be in the wires. Go to the zone valve and locate those two wires and jump between them. Now what?

EBEBRATT-Ed

You should get 24 volts at terminals 1 & 2 on the taco zone valve with the thermostat calling for heat. That is the first thing to check

desiraelynn07

Jamie Hall we have tried that and still don't get heat.
Ebebratt- Ed I'm going today after work to buy one 

desiraelynn07

There is power at the thermostat but the taco value has no power its not reading anything?

Jamie Hall

Something is very wrong with the wiring and connections. When you say there is power at the thermostat, I presume you mean that you can read 24 VAC between two wires. Which wires? Are two wires at the thermostat, or three (or more? What do you read for voltage between the two wires when the thermostat is calling for heat?

EdTheHeaterMan

Has any looked at the fact that the valve may be working just fine and there is air in the line so there is no heat. To check that out you just need to manually open it with that lever.

desiraelynn07

Jamie Hall we only have 2 wires , a red and black at the thermostat. When wired it reads 0, but when putting testers to Bare wires it reads 25

Jamie Hall

Let's go back a few steps here. You have two wires at the thermostat. A two wire thermostat is a simple switch which happens to be actuated by temperature. When that switch is open, or the two wires are disconnected from the thermostat and from each other, you should get 24 VAC across the two wires. When the switch is closed -- the thermostat is calling for heat -- you should get 0 VAC.

Down in the basement find the same two wires. If the thermostat is calling for heat, there was no voltage between the two wires at the thermostat -- and therefore no voltage between them at the zone valve. However, you SHOULD have 24 VAC between either of those two wires (the one still connected, and the one you disconnected) and the zone valve terminal which you disconnected the wire from.

desiraelynn07

I just went to ace and bought a new thermostat now the taco valve is reading 24 so I believe we bought the wrong thermostat. But we are still not getting heat 

EBEBRATT-Ed

@desiraelynn07

When the thermostat is calling for heat (either the thermostat is calling or if you jump the two thermostat wire together) you should have 24 volts between terminal 1 & 2 on the tacl valve and the valve should open. It takes a min or two for Taco valves to open.

To tell if it is open or not look at the picture in @EdTheHeaterMan post. If the lever is down and you can slide it up easily the valve is open. If the lever has tension on it the valve is closed.

If the valve is open and you have no heat then you have another issue

desiraelynn07

@EdTheHeaterMan @EBEBRATT-Ed
The lever has tension and the valve is closed.
How do you get air out of the line?

EdTheHeaterMan

You can eliminate the thermostat from the equation. This is the process of elimination first step. Eliminate the thermostat by removing the wires from the thermostat and connecting the wires together. Yes… that is right… if you take the wire off the thermostat W and the other wire off the thermostat R and connect those two wires together, then you have eliminated the thermostat from the circuit.

You can then see if removing the thermostat from the circuit solves the problem. This way you do not need a new thermostat to see if the old thermostat is the cause of the problem. If the heat happens with this test, then you can be sure that the thermostat IS the problem and purchase a new thermostat. IF however this test does not make heat happen, then the thermostat is probably not the problem.

Now that you have replaced the thermostat and you still have the same problem, What will you check next? That is what I used to say to my technicians when they made a diagnosis that involved an expensive part or a time consuming repair.



Now get yourself a multimeter and see if there is 24 volts on 1 and 2 of the zone valve. If yes then wait 2 minutes to see if the valve opens. If no then check the transformer to see if it is good with the multimeter and see if there is 24 volts at the transformer. If there is then take a temporary wire from R on the transformer and put it on terminal 1 on the zone valve. Then take a temporary wire from C on the transformer and place it on terminal 2 on the zone valve. DO THIS WITH ALL THE OTHER WIRES REMOVED FROM THE PROBLEM ZONE VALVE, SO YOU DO NOT CROSS CIRCUITS, AND DAMAGE THE TRANSFORMER OR THERMOSTAT

Now see if there is 24 volts at #1 and #2 on the zone valve. If yes then wait 2 minutes to see if the valve opens. If the valve does not open then use the manual lever to open the valve and see if heated water will pass the valve and go to the radiators.

Im sorry if I sound like a second grade teacher, but some of your replies indicate that you are not fully understanding what others are telling you. So I go one step at a time to be sure you are clear on the proper steps to diagnosing and using the process of elimination before you buy any more parts.

Mr. Ed

EDIT

PS

Unless you get 24 volts to 1 and 2 on the zone valve, you will not know if the zone valve is the problem or if the sone valve actuator is working.

PLEASE, LET US ALL KNOW WHAT HAPPENS WHEN YOU DO THIS TEST.