hot water won't turn off | Central Heating Forum | Page 2 | Plumbers Forums

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Don't know if fitting a new complete motorized head instead of just the synchron motor would make any difference or not. In the meantime suggest fitting (again) the motorized head from the CH to the HW and wire it up by removing/using the wires from the "old" HW head, let the wires disconnected from the other actuator and see what happens.
 
Disconnect the orange wire and see what happens or what shouldn't happen.
I disconnected the orange wire and turned the power on. The MV still moved around and engaged the switch but the boiler didn’t fire up (I guess that’s what the orange wire does :))
 

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Don't know if fitting a new complete motorized head instead of just the synchron motor would make any difference or not. In the meantime suggest fitting (again) the motorized head from the CH to the HW and wire it up by removing/using the wires from the "old" HW head, let the wires disconnected from the other actuator and see what happens.
When I swap the heads over and the wiring then the same thing happens. But before I changed the wires over I tried just swapping the heads. So basically to get the Hot Water is now controlled by the Heating side of the programmer - Doing this solves the issue - it works as it should - to get the MV to operate I had to turn on the HG60 and the programmer on and then the MV kicked in as normal to turn the hot water on. Brilliant! But then the other valve opens the heating valve and turns the Heating on without being asked! So must be a wiring issue? Even though I haven’t moved any wires around before the issue started? I posted a pic of the wires in the post earlier
 
Don't know if fitting a new complete motorized head instead of just the synchron motor would make any difference or not. In the meantime suggest fitting (again) the motorized head from the CH to the HW and wire it up by removing/using the wires from the "old" HW head, let the wires disconnected from the other actuator and see what happens.
When I swap the heads over and the wiring then the same thing happens. But before I changed the wires over I tried just swapping the heads. So basically to get the Hot Water is now controlled by the Heating side of the programmer - Doing this solves the issue - it works as it should - to get the MV to operate I had to turn on the HG60 and the programmer on and then the MV kicked in as normal to turn the hot water on. Brilliant! But then the other valve opens the heating valve and turns the Heating on without being asked! So must be a wiring issue? Even though I haven’t moved any wires around before the issue started? I posted a pic of the wires in the post earlier
 
I have taken the fronts off all the controls but the Lee is still 240v on the orange and the grey cables and when I turn the far right switch on or off this turns the hot water on and off without any controls. Is there a wire I need to move etc?? I have tried it with the MV head from the heating valve and re wired it but it does exactly the same thing so can’t be the head as the Heating head works fine when it’s on the Heating.
 

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Have you checked the wiring at the ST9400A controller in case there is a extra permanent live connected by mistake to the "HW Off" which is used for a Y plan configuration or something along those lines.
 
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You have a bad port valve or one permanently calling do you have any voltage on the browns on the port valve wires ?
 
Need to test no point in throwing parts at it
i have taken the program unit and the HG60 module off. The power is on. you should make out the numbers behind the wires. with the black wire on the tester in space 3, I have 240v in lines 1, 7, 8 and 0. The HW is on and won’t switch off. Even though the controls are removed.
 

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Have you checked the wiring at the ST9400A controller in case there is a extra permanent live connected by mistake to the "HW Off" which is used for a Y plan configuration or something along those lines.
I notice that this is not how it says it should be wired on the back of the program box
 

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240v on either 6 or 8?
 
It’s s plan so programmer is correct
 
Turn the fused spur off and remove the grey wire and make safe (when you turn power back on this might be live)
 
Now try your heating and hot water systems eg one at a time does everything work eg boiler come on pump etc
 
Turn the fused spur off and remove the grey wire and make safe (when you turn power back on this might be live)
I have just realised that we have had some underfloor heating out in downstairs in an extension and they wired it in next to the boiler. Could they have wired something in wrong there? We had noticed that our water all winter was really hot and we had been using a lot of oil. I think I have only noticed this issue when the heating finally went off. Maybe this has been happening since the new bit of wiring went in!
 
Yep maybe do you have an extra port valve by the manifold?
 
Yep maybe do you have an extra port valve by the manifold?
I think the grey wire I have disconnected upstairs is the one in the frost stat in the screw without a number to the right of slot 4
 

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Was the stat up ? You may have to lift it due to upto temp on the cylinder
 
Test the whole system eg leave it a couple of days and see how it goes / what doesn’t work

Don’t forget to turn the star back down to 60
 

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