heating zone won't shut off

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Old 10-17-13, 05:49 PM
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heating zone won't shut off

I have an old hot water heating system with 5 zones. One of the zones is heating the radiators even though the thermostat is set low. The zone valves are mechanical. I have tried rotating the set knob (open, auto, closed) back and forth with no change. Could the old valve be frozen in the open position. If so, can I add an electric valve above it? Could it be an air lock somewhere? The pump isn't running. The only radiators heating up are the 2 closest ones.

I'm new to this system and don't want to get ripped off. Any help would be appreciated.
 
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Old 10-17-13, 05:59 PM
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The zone valves are mechanical
They are?

Maybe what you are looking at is not a zone valve at all, perhaps it's a 'flow-check' valve.

The only radiators heating up are the 2 closest ones.
I suspect that what you are experiencing is known as 'thermosiphon', or 'gravity flow', or 'ghost flow', and probably some other not so nice names as well.

What this means is that the hotter water is 'floating' up into the zones because it is less dense than cooler water... and you are getting unwanted heat.

You will need to tell us a number of things:

1. make and model of the boiler.

2. make and model of the 'mechanical' zone valves.

3. some others I haven't thought of yet.

You will also need to take a bunch of pictures so we can see what you are working with and eliminate confusion that may come from nomenclature...
 
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Old 10-17-13, 06:12 PM
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Are zv on supply or return. Are you getting your domestic water from your boiler or do you you have a desperate tank. If your zv are on the return and you're boiler is used for hot water it's most likely the closest rads and it's caused by gravity. In your supply you should have a Flo check valve. It only allows the water to pass when the pump is on. It may be open or not working. With the boiler on feel the supply pipe after the Flo check. If its hot its leaking by.
 
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Old 10-18-13, 05:30 PM
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The "valve" is on the supply line. The writing on it says - 124U Triplex Thermolator. Above one of these someone installed a White-Rodgers zone-a-flow elec valve no 1361-104. The boiler is a Weil-McLain Gold CGa.
I took a couple of pictures but don't know how to attach them.
 
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Old 10-18-13, 05:58 PM
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That zv is an 11/4 24v zv and has a manual lever on there. Check to see if it has been moved. If so put it back to auto. If its in auto will need more info. Tankless hot, etc.
 
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Old 10-28-13, 06:02 PM
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I'm not having trouble with the zone that has the elec valve. One of the other 4 zones with the mechanical (flow check?) valves is not closing. I think it is set to auto, but the large knob with a line marker on it is missing from the stuck valve. That one has an unmarked bolthead that I set using the TLAR method. To answere another question - this is a closed system. It just heats the house, not our hot water.
 
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Old 11-02-13, 08:38 PM
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Hot water boiler with two zones has one zone that won't stop working. I disconnected the thermostat upstairs but it continued to run. If if I shut off the power, he valve closes but as soon as I turn on the power, it opens.

I shut the valve that is just above the Honeywell zone valve but figured it wasn't a good idea to have the boiler constantly working with the water having nowhere to go until the other zone calls for heat. The strange thing is that I went back and discounted one wire from the zone valve that is connected to the thermostat and when I turned the power back on, it stayed off. Weird because when I had the thermostat disconnected upstairs, it would continue to run. Does this sound right? Plumber not coming until Monday.
 
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Old 11-02-13, 08:50 PM
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You disconnect the wire at the thermostat and the zone stays open.

You disconnect the thermostat wire at the zone valve and it closes.

This tells me that your thermostat wire has a short in it.

If that is true, then you don't need a plumber, you need an electrician to pull a new thermostat wire for you.
 
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Old 11-02-13, 09:14 PM
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Is it ok to keep the water valve closed? I'm probably going to open just in case the zone valve somehow turns on. The wire was my first guess after I disconnected it at the zone valve and the boiler stayed off.

Thanks for your input.
 
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Old 11-03-13, 09:23 AM
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Is it ok to keep the water valve closed?
Closing the valve on just that zone? With the boiler still calling for heat?

No, not a great idea.

I would disconnect the wire at the zone valve, lock it into the manual open position and let that zone get heat when any other zone calls.

If you do this, you might find that the open zone tends to get too warm... if it does, then just close the zone valve again.
 
 

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