Thermostat won't trigger circulator but triggers zone valve


  #1  
Old 10-20-05, 05:55 PM
piz
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Thermostat won't trigger circulator but triggers zone valve

I have a 5-zone hydronic system. 4 of the 5 zones work perfectly. Thermostat clicks on, circulator starts, zone valve opens, damper opens and the heater starts up.

However, for one zone, when the thermostat goes off, it triggers the opening of the valve for the zone but it does not trigger the circulator pump, damper or heater. I changed the batteries in the thermostat thinking there wasn't enough voltage to trigger everything but this did not work.

Any help would be greatly appreciated.
 
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Old 10-20-05, 06:09 PM
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Zone valve

If you are sure the zone valve is opening, it sounds like you either have a broken wire between the zone valve & the boiler control, a loose connection, or a bad zone valve end switch. If this is a Honeywell or Erie zone valve, there is a small lever at the bottom. With the thermostat calling for heat this lever should be easy to move. Push it all the way to the right. If the boiler now comes on, the micro switch is bad.
 
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Old 11-06-05, 09:53 AM
ronp100343
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I Have The Same Problem

I have a four zone and only one works. All open the valve, but nothing else happens. I did slide the switch which was openm but nothing. There is a safty warning on the valve regarding electrical shock, is this really dangerous to tamper with or replace? Is the valve the problem? It appears that the wires going to a large board are intact. Also how expensive are they. They are Honeywell.

Thanks.
 
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Old 11-06-05, 04:31 PM
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Large Board?

Does this board have a numbere on it? Do you know its function?
 
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Old 11-06-05, 05:56 PM
ronp100343
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Thanks For The Quick Reply

There is no number on it. All it says is it is a four zone terminal board, Each of the thermostat's 2 wires come in and 4 wires come out to the various things like I think one is the limit switch, and the other I didn't check, mabe the valve now that I am thinking of it. Each valve has 4 wires also.
 
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Old 11-06-05, 06:04 PM
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RonP

An easy way to check if the end switch is the problem is to turn up the thermostat & give the valve time to open. Move that little lever on the valve. If it moves easily the valve is open. If the valve is open, jumper across the two terminals marked "switch" or "end switch". If the circulator now comes on the previously mentioned end switch is bad.
 
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Old 11-07-05, 08:38 AM
ronp100343
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Thanks Again

If the valve is open, jumper across the two terminals marked "switch" or "end switch".
Well, I know the valve opens, but where are the wires to the end switch? I see some wires under the cover that seem to be sealed or something. Also what about the warning about voltage?

What if the switch is bad? What do you replace? The whole valve? Are there parts to replace rather than having to sweat a new valve in place? I am not a plumber or a contractor, just a homeowner.
 
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Old 11-07-05, 04:32 PM
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Zone valves

Remove the cover. There should be two wires hooked to a small electric motor. Those are not the wires you are interested in. The other two (usually a different color) should go to a small switch. This is the end switch. If you can provide the model number of the valves, I can probably tell you if you have 24 volt or 120 volt valves.
 
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Old 11-07-05, 07:02 PM
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I am sure that it is 24 volts as that is what the "board" refers to. Here is the model number though. F3 9342.

Thanks again.
 
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Old 11-08-05, 04:14 PM
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RonP

I think that 9342 is a date code (42nd week of 1993) the model number of the zone valve should be something like V8043E-1012 (Letter, 4 digit number, letter, 4 digit number), if it is a Honeywell valve. That number should be on the inside of the cover on a label.
 
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Old 11-08-05, 10:49 PM
ronp100343
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The number is : v 8043e1061
Thanks.
 
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Old 11-08-05, 11:02 PM
ronp100343
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Thanks Again

The number is:v8043E1064
 
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Old 11-09-05, 05:46 PM
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Zone valve voltage

All V8043 series valves are 24 volts. If you touch the bare ends of the wires, you might feel it but it is certainly not life endangering. As always when working on electrical components, it is a good idea to turn off the power when touching wires.
How to test end switch: With power turned off, remove the cover of the zone valve & locate the end switch wires. Follow these wires to where they join other wires or the terminals on the control board. Put a jumper wire across the terminals where the end switch wires connect to the control board. Turn the power back on & set that zone's thermostat to call for heat. If the valve opens & the circulator comes on, the end switch is bad. In the past I have found them at Radio Shack or other electronics stores. Far cheaper than replacing the whole zone valve power head.
 
 

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