Taco zone valve not closing

dford1013

Hi guys, I have 2 zones in my house that have taco zone valves. Getting overheat upstairs like my valve won't close. Also I have power on terminals 2 and 3 when the thermostats are not calling for heat. Is this normal? I have 1 taco gold, 1 green for baseboard heat and a Honeywell V8043E1012 for my indirect water tank. My controller is a hydrostat 3150. Could the ball in the valve be getting stuck or could this be a wiring problem? When i turn up my thermostat, terminals 1 and 2 get power but when there is no call for heat 2 and 3 have power and the valve lets hot water through. Confused!!

newagedawn

id bet the zone valve is bad, happens

Tim McElwain

Disconnect power from the valve in question. Then remove the head.Now take a hammer and very gently tap the valve body to attempt to free the body. Tap very gently. Then put the head back and see if it opens and closes. I have been doing this for years, also make sure the old green head that the internal contacts are making and breaking.

dford1013

When the thermostats not calling for heat should terminals 2 and 3 on the zone valves have 24v? Thank you for your help!!

Tim McElwain

Terminal 2 and 3 are your end switch on the zone valve. They are usually tied into a T - TV circuit on a relay which has a 24 volt transformer in the relay, so yes across 2 and 3 wire open you should read 24 volts as you are reading across the secondary of the transformer in the relay. In fact in some case depending on the relay you may read a little less than 24 in fact 15 to perhaps 18 volts which is fine. The fact that you are reading 24 volts says the switch (2 and 3) in the zone valve is not made so the system should not be running off that zone.

dford1013

The zone valve is brand new. I took the head off and sprayed the valve body with wd40. It seems to be going in and out all right. Amazingly I think that may have done the trick

dford1013

Spoke too soon. Not sure what's going on!? The valve body feels like it moves in and out without problems but when I turn the thermostat on for the downstairs, the upstairs baseboard are getting hot.

dford1013

I believe the wiring is all correct. Terminals 1 & 2 on the valve do not have 24v when the other valve calls for heat so I know the plunger on the head is not actuating the valve.

STEVEusaPA

Follow Tim's advice. Disconnect 1 & 2. If you're getting heat when the other zone is calling, then you'll have to replace the valve body.
I'm assuming you were unable to free it as described.

lchmb

if it's brand new it could be some solder is stuck in the valve from install...

ericmmff

The taco zone valve is normally closed. If you have 24 v at 2 and 3 than the valve is open due to s call for heat. Keeping the zone valves all the same makes wiring much easier. The wiring diagram that came with the Honeywell valve will help.

STEVEusaPA

ericmmff said:

The taco zone valve is normally closed. If you have 24 v at 2 and 3 than the valve is open due to s call for heat. Keeping the zone valves all the same makes wiring much easier. The wiring diagram that came with the Honeywell valve will help.

I think you have that backwards. Re-read what Tim said. If you have 24V at 2 and 3, your end switch is 'open'. You're getting the 24v from the aquastat t-t. When the end switch is closed you read 0 across 2 & 3.

ericmmff

Maybe Im wrong.
Best thing to do is get rid of that garbage and buy 3 new Automag zone valves. Made right here in NEPA. Then there will be no confusion

Joe Mattiello

I suggest you call Taco tech support for additional support troubleshooting your valve. Tim, explained it accurately, but perhaps I can explain further so you grasp it. The valve needs 24 volts across 1, and 2 for valve to open. Terminal # 1 is usually wired to one side of thermostat, and the other side of thermostat is wired to one pole of transformer, so the thermostat works as a normally open switch. The other side of transformer is wired to terminal # 2. When air temperature drops below set-point, thermostat closes to complete circuit energizing the valve to open. It takes approximately 1.5 minutes for valve to open, and end-switch (terminals 2 & 3) to close. Terminals 2 & 3 are wired to thermostat terminal T, & TV to enable boiler. Your boiler aqua-stat has its own 24 volt transformer which is what you’re measuring across terminals 2, and 3 on the valve, assuming you’re wired correctly.
If you're experiencing overheating, it's possible your thermostat has perpetual demand keeping zone-valve open. Another scenario worth investigating, is wires are crossed, and when an adjacent zone calls for heat it's energizing the suspect zone too. If you’re still experiencing ghost flow, I suggest you call Taco tech support at 401-942-8000 and talk to one of 9 technicians anxious to help

lchmb

Taco is american made and I for one prefer them. No need for name calling of another product due to you not understanding them..

dford1013

Going to call Taco. Thank you for all your help guys. I appreciate you taking the time. Will let you know what they say.

ericmmff

By garbage,I meant the mixing of zone valves.
Taco is a fine product. I use it all the time.
I'm at work so I should have explained it better.
Maybe I should stick to ditch digging