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Boiler zone issue

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Raymodj
Raymodj Member Posts: 24
in Gas Heating
Initially had trouble with heat not always working on for 3rd zone we had installed 8 years ago. Removed thermostat, touched wires, and heat came on. Installed new thermostat and heat came on.. Fixed, right? Wrong. Took me a month to notice because it was so cold,, but heat wasn't ever turning off. Uninstalled new thermostat, separated the wires, heat stayed on.

Went to boiler, flipped the zone from auto to on, then back to auto. Couldn't always tell, but I did see and hear motor move the switch once, but maybe not fully. It's a V8043E5012 Honeywell with a quick disconnect, so I completely took it off, disconnected from system. Was going to replace it or the motor. Then I noticed that it didn't matter which way I manually turned the internal valve "knob", (see photo) the heat still stays on very hot. Only way to turn it off was by turning the water valve to the radiator off.

So am I just not thinking this through, something I'm not understanding, or is it problem with internal parts?


Comments

  • HomerJSmith
    HomerJSmith Member Posts: 2,441
    edited March 2022
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    The valve could be miss wired, perhaps installed backward, have an impediment holding the stopper open, a high pressure pump pushing water past the stopper, a short in the thermostat wires, or have a ghost flow up the return pipe.

    Disconnect the thermostat wire (only one wire is necessary) at the zone valve and see if the problem is resolved. If it is, then I would suspect a short in the thermostat wires.

    When you move the manual lever, if the valve is open, the lever moves easily, back and forth. If the manual lever moves with difficulty (pushing against the springs) the valve is in the closed position.
  • Raymodj
    Raymodj Member Posts: 24
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    Follow up question. If I drain this zone, can I open this faceplate and replace the internal ball valve or whatever is causing the problem? Based on just looking at it (picture in above post) it looks like it might be possible.

    I would just replace the whole thing, but I haven't stepped up my game to soldering copper pipes.
  • HomerJSmith
    HomerJSmith Member Posts: 2,441
    edited March 2022
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    You can replace the ball stopper with out soldering a new valve housing in, but I would want to check all the other possible causes first. You have the power head off, does the actuator move freely. Take a small crescent wrench or pliers and move it. Does it move easily?

    Sometimes a bit of solder, when soldering the pipe to the valve, bypasses the pipe stop in the valve and will interfere with the stopper closing, holding it partially open.

    I have actually found a wood sliver in a honeywell valve, which must have happened during construction.

    If you do solder in a new valve, do it with the stopper in the open position.
  • Raymodj
    Raymodj Member Posts: 24
    edited March 2022
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    @HomerJSmith. I have completely removed the thermostat and the zone valve, nothing wired for this zone. The actuator moves easily by hand about 1/4 turn back and forth. Tried a pliers to see if it would turn farther, but didn't want to apply too much pressure. It definitely seems to hit a stop in each direction.

    Forgot to mention this zone worked fine for 7 - 8 years.




  • HomerJSmith
    HomerJSmith Member Posts: 2,441
    edited March 2022
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    That's the limit of its movement. Don't force it. Take a pic of the offending valve from further away showing the piping arrangement.

    You'll need snap ring pliers to remove the stopper assembly.
  • Raymodj
    Raymodj Member Posts: 24
    edited March 2022
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    Edit: deleted tablet pics.

    From phone:




  • HomerJSmith
    HomerJSmith Member Posts: 2,441
    edited March 2022
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    It is possible you are getting ghost flows up the return blue pex pipes. Where is your expansion tank? Is that long silver thing your tank?
  • Raymodj
    Raymodj Member Posts: 24
    edited March 2022
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    Good call! I turned on both water valves, and return pipes heat up fast, flow stays cool at first.  Thank you!  Very happy you recognized that before I drained and opened it up.

    Not sure how to determine cause and fix, but I've started googling.  Since it worked fine for years, something failed?
  • Raymodj
    Raymodj Member Posts: 24
    edited March 2022
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    I always just assumed the zone valves were on the supply side, but while reading about ghost flow I saw that they are on the return side. I guess I need boilers for dummies. Looking at the pic, the higher set of pex pipes is heating up first, which is the supply side. Which is obvious when I follow the pipes back.

    So I'm back to square one.

    Yes, the expansion tank is up there at the ceiling, it's black cast iron. That silver is mostly glare from an led light I put up there.
  • pedmec
    pedmec Member Posts: 973
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    if your zone valves are on the return side of your boiler then your boiler is piped in backwards (which i don't think is the case). return to boiler is always on the lowest tapping on the boiler. you should check the arrows on the valve body. the devil is in the details. zone valves are recommend on the return side but can be installed on the supply side.
    i wouldn't just try and replace the ball. the Honeywell 8043 zone valves that i work on do fail at the ball. the problem with just changing the ball is that the seat is actually getting eroded due to water flowing past the valve in a smaller area of flow. the increased velocity causes erosion. and you only find this out after you put the system back on line. its one thing to change a powerhead but its another to start changing internal parts. change the whole valve and your good to go. no second guessing

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