Hot water but no heating
- Thread starter sd60
- Start date
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Yes! Do you have any zone valves or maybe a 3 port mid position valve in your system. Its highly likely this is where the problem lies. either valve not moving to correct position or if it is then microswitch failure
Is it a 3 port motorised valve
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As I understand the 2 port, when CH is called for the motor moves the valve to open position, when in the open position it triggers microswitch. When demand is satisfied or CH no longer called for then power is removed and valve returns to closed position by a return spring.
You should be able to tell if motor is driving valve forward or if valve is returng under spring pressure. It may be possible to remove actuator head from valve spindle to watch it as you try it. If it does move across ok then the microswitch which supplies power to the boiler is where the problem lies.
If you look at wiring diagrams the norm is a live wire and neutral wire to drive the motor. Then another live wire to the microswitch and a switched live wire from microswitch to boiler. A replacement actuator head would cover both motor and microswitch. unless of course the valve itself is stuck fast, but you can try that when you remove the head.
hope it helps a little.
You should be able to tell if motor is driving valve forward or if valve is returng under spring pressure. It may be possible to remove actuator head from valve spindle to watch it as you try it. If it does move across ok then the microswitch which supplies power to the boiler is where the problem lies.
If you look at wiring diagrams the norm is a live wire and neutral wire to drive the motor. Then another live wire to the microswitch and a switched live wire from microswitch to boiler. A replacement actuator head would cover both motor and microswitch. unless of course the valve itself is stuck fast, but you can try that when you remove the head.
hope it helps a little.
Well you've made a bit of headway, at least you know the valve is free.
and I think you can forget the microswitch for the moment.
So the next stage is to prove that electric is getting to the head when the room stat is turned up. you can test that with a neon screwdriver.
It does look more like a duff motor inside the head which you can replace for about £15.
and I think you can forget the microswitch for the moment.
So the next stage is to prove that electric is getting to the head when the room stat is turned up. you can test that with a neon screwdriver.
It does look more like a duff motor inside the head which you can replace for about £15.
Hi. Similar problem here... I have an ancient (20+yr) system with Potterton Netaheat 10-16 boiler (which I have repaired myself twice so far - ignition generator and relay).
Right now, I have CH (thank goodness), but no HW. All symptoms point to a stuck motorised valve. Problem is, I can't find it. I can find the main pump, which I had to remove a kitchen unit to access, but not valve.
To the left of boiler, pipework is boxed in, where timer controller is mounted. I can't believe I'd have to dismantle this to access valve!
Any ideas where to look please?
Many thanks in advance,
Alan.
Right now, I have CH (thank goodness), but no HW. All symptoms point to a stuck motorised valve. Problem is, I can't find it. I can find the main pump, which I had to remove a kitchen unit to access, but not valve.
To the left of boiler, pipework is boxed in, where timer controller is mounted. I can't believe I'd have to dismantle this to access valve!
Any ideas where to look please?
Many thanks in advance,
Alan.
Thx. Will take a look, then start new thread if necessary. Apols & thanks
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