Hello, I have a vented system with independent motorized valves for heating and hot water. The heating works fine, boiler comes on and off controlled by the room thermostat, all radiators get hot. Trying the just hot water, the boiler comes on runs for a short time then switches off, pump stops and valve closes.I can feel the pipe warming up both sides of the valve. Left alone it tries again about an hour later. I thought tank thermostat, so I disconnected it, boiler did not come on at all (as expected), I shorted it and the boiler did the running for a couple of minutes trick. I think this means the thermostat is OK. I thought air lock, so I turned the pump up to max and can hear the water circulating and the bottom of the coil gets slightly warm before the boiler switches off. Now I'm stuck, some guidance as to where to look next would be appreciated. Thanks
Radiators working but no hot water
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No faults come up on the boiler? Does it go through a programmer? Maybe try linking that out.
No display on the boiler, so no faults. There is a programmer with a billion wires to the back of it. Not sure how I would bypass that.
Switching on heating and hot water at the same time it all seem to work ok, then after the usual couple of minutes the Hot water valve closes as if it was at temperature, which it can't be because the thermostat is shorted. The boiler continues to run as normal for the heating
Switching on heating and hot water at the same time it all seem to work ok, then after the usual couple of minutes the Hot water valve closes as if it was at temperature, which it can't be because the thermostat is shorted. The boiler continues to run as normal for the heating
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Need to be testing for voltages really. Can you disconnect the motorised valve actuator for hot water and just get it via the heating for now?
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Photo?
The Motorized valve can be set open manually, we have hot water so there is no panic. When it's sunny the solar panels provide more than enough hot water, the boiler hasn't been used since February, I wonder if that idle time has caused an issue.
Has it worked OK in the past?
Sounds to me like the valve isn't opening, so the flow goes through the bypass. Assuming it's wired correctly the microswitch is closing, so maybe the actuator is not opening the valve.
Worked absolutely fine for a good number of years.
The valve sounds and feels like it's opening: the manual lever goes floppy when the valve is open.
Photos showing wiring, there are plenty of wires but not quite a billion. There is a hand written note labeling the connections in the Airing Cupboard, looks like it matches the letters and numbers in the controller wiring
Attachments
Do I understand this correctly: In normal running the motor is under power holding the valve open against a spring and the other two (auxiliary) wires tell the controller the state of the valve. After a couple of minutes the motor gives up and lets the valve shut and the auxiliary tells the controller which stops the pump and boiler ?
yep basically that the motor is breaking down when in use
You can check it
with clock demanding HW you will get 240v on the brown wire to valve which opens it
when the valve closes and boiler and pump go off check if you still have 240v on brown if so then its the motor
If your not getting 240v then you follow it back to cylinder stat then clock to see were your losing the 240v
You can check it
with clock demanding HW you will get 240v on the brown wire to valve which opens it
when the valve closes and boiler and pump go off check if you still have 240v on brown if so then its the motor
If your not getting 240v then you follow it back to cylinder stat then clock to see were your losing the 240v
I would remove the actuator, and check that the valve works smoothly, maybe turning the stem with pliers. It should only move about 1/4 of a turn. And that the valve stem engages correctly with the actuator, and there is no damage.
Then call for HW, make sure the valve is open manually, and see if the boiler continues to run.
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You are correct. 240V steady on the brown wire when the valve closes. It's time to buy a new motor
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