What closes a zone valve

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Old 12-28-08, 02:27 PM
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What closes a zone valve

I am using Honneywell zone valves V8043E 1020 and two of them appear to be staying open. A motor with a gear on it opens the valve when the thermostat calls for heat, in doing so puts tension on two springs. Do the springs pull the valve closed when the thermostat is satisfied, or does the motor run backwards. Any ideas, Thanks
 
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Old 12-28-08, 02:41 PM
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The motors run on 24 volts AC, which is normally supplied by a heat call from your thermostats.

The motor operates a rack and pinion drive to open the valve. When power is removed, the spring tension pulls the rack back, closing the valve. The motor will turn backwards, but this is passive and spring driven on the return when power is removed. The drag of the motor armature also serves as a governor, slowing the closing speed.
 

Last edited by radioconnection; 12-28-08 at 03:12 PM.
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Old 12-28-08, 03:58 PM
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Thanks for the help, I need to figure out what is making them stick. I took the motor off of one of them and I can manually open and close the valve freely.
 
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Old 12-28-08, 04:18 PM
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Some folks remove one of the springs to slow the valve closing time... You have both springs, so there is something wrong.

Does the power head open and close normally the start and end of a heat call when it is removed from the valve body? You can have someone run the stat up and down while you watch. Are you sure there is no voltage on the motor leads holding it open, say from a stuck stat'? If the motors are sticking replacement are available.
 
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Old 12-28-08, 07:00 PM
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With the one motor off the valve body and still wired up and powered up I had the wife turn the thermostat up and down. When turned up the motor would run and when turned down the motor would stop. I put the motor back on tonight and will see what is does overnight and tomorrow morning. With the other motor on the valve body and my son turning the thermostat up and down nothing on the valve mechanism moved. I checked power at the valve when it should be closed and I get 11 volts on one and 8 volts on the other, is that enough to keep it open? If it is I would assume it would be the thermostat that is the problem. Thanks again
 

Last edited by Jerome; 12-28-08 at 08:20 PM.
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Old 12-29-08, 05:18 PM
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I did not think that the 24 volt circuit was a world of its own, I guess it has to be, ground and all. In the past I was grounding off a piece of greenfield and also a heating pipe. I have 28 volts at the transformer, 27 volts at the motor when running off the valve, zero at the motor when the thermostat is not calling for heat. So the valve should be closing. I can turn the motor with my fingers using the little gear on the shaft. It turns a little hard, but I don't know how much force the springs that close the valve create either. What do you think, buy a new motor?
 
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Old 12-29-08, 05:40 PM
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27 VAC should be enough. Try swapping power heads between zones (if you feel confident doing so!) and see if the problem follows the head, or stays with the valve.
 
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Old 12-29-08, 06:22 PM
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I have 3 zones, I first noticed the problem on 1 zone. The next night I noticed the same problen on the second zone. Now all three zones have the same problem. Something is messed up somewhere. This system worked flawlessly for 20 years now all 3 zone valves seem to have went ca-put in a matter of days.
 
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Old 12-30-08, 03:56 PM
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I was able to fix the zone valve that I had taken the motor off of. I took the motor assembly apart, first the gear box end. That is a little gear box assembly with no grease of any kind in it. The little gears just run on shafts like in your grandfather clock. I then took apart the other end which was just a cover over the end of the motor. Out came a tea spoon of rust, that rust was jamming the motor so the springs did not have enough power to spin the motor backwards. The mechanical advantage was backwards on the spring side also so that did not help. Take apart the other two tomorrow and be back in business. Thanks for your help radio connection
 
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