HW works ok but no CH
- Thread starter Rod1956
- Start date
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As twgas suggested can you check if there is 240V on the brown wire of the CH valve, when the room thermostat is ON ?
If the brown wire is Live and the blue wire is close to zero Volts, the valve actuator will either work or it needs replacing.
If the brown wire is Live and the blue wire is close to zero Volts, the valve actuator will either work or it needs replacing.
Here's my wiring - the junction box is British Gas' idea - the connection goes direct into the motorized valve as you can see.
I tested the connections with the thermostat OFF and only one wire was live.
With the thermostat ON - there are 2 live connections
- so I'm guessing both the thermostat and controller are working ok ?
would a faulty pump cause my problem ?
I tested the connections with the thermostat OFF and only one wire was live.
With the thermostat ON - there are 2 live connections
- so I'm guessing both the thermostat and controller are working ok ?
would a faulty pump cause my problem ?
That looks OK so far. If the valve was working properly it would move the lever right across, a microswitch would operate and the Orange wire would go Live causing the boiler to fire up.
Have you tried holding the valve fully open manually to see if any of this happens?
It may be that the valve and microswitch have been totally knackered at the same time but that makes me a bit suspicious there may be something else at fault. A multimeter across the brown and blue showing 240V would be a lot more convincing.
I doubt there's anything wrong with the pump, assuming you can hear it running and can feel the hot water circulating in the direction of the storage tank OK.
Have you tried holding the valve fully open manually to see if any of this happens?
It may be that the valve and microswitch have been totally knackered at the same time but that makes me a bit suspicious there may be something else at fault. A multimeter across the brown and blue showing 240V would be a lot more convincing.
I doubt there's anything wrong with the pump, assuming you can hear it running and can feel the hot water circulating in the direction of the storage tank OK.
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Thanks for this - at least something looks right.
Sorry to be so thick, but I can't hear anything in the airing cupboard.
The only time I hear anything is when I press the HW Advance button.
When should I hear the pump ? and what should it sound like ?
Would a faulty pump cause the boiler not to fire up ?
Sorry to be so thick, but I can't hear anything in the airing cupboard.
The only time I hear anything is when I press the HW Advance button.
When should I hear the pump ? and what should it sound like ?
Would a faulty pump cause the boiler not to fire up ?
I've done some more testing.
With the thermostat ON - I held the lever on the valve in the picture against the pressure and tested the orange wire - it wasn't live.
With the thermostat ON - I pressed the hot water advance switch
The lever on the other motorised valve moved itself - there was a lot of glug glugging around the pipes.
I then tested the orange wire in the picture and it was live
can you make sense of this ?
With the thermostat ON - I held the lever on the valve in the picture against the pressure and tested the orange wire - it wasn't live.
With the thermostat ON - I pressed the hot water advance switch
The lever on the other motorised valve moved itself - there was a lot of glug glugging around the pipes.
I then tested the orange wire in the picture and it was live
can you make sense of this ?
That last bit sounds right. Once the boiler has received the 240V demand from the hot water side of the system that voltage will come back via the boiler and also appear on the Orange wire going to the CH valve.
It's not looking good for the CH 2-port valve though. Can you get hold of a multimeter to check the voltages properly?
As far as replacing it goes, it may be possible to remove and buy only the head, leaving the plumbing untouched.
It's not looking good for the CH 2-port valve though. Can you get hold of a multimeter to check the voltages properly?
As far as replacing it goes, it may be possible to remove and buy only the head, leaving the plumbing untouched.
if you either put an e mail in your profile
or e mail me i will send the fault finding guide
sent
or e mail me i will send the fault finding guide
sent
With room thermostat ON there should be ~240V between Brown and Blue on the CH valve.
If there is and the valve is making no attempt to move, it's actuator is bust.
That's right. Make sure it's set to 240V AC ~ or it won't read correctly.
Make sure the probes are connected to the correct terminals on the multimeter for Voltage measurement (V/Ohms and COM).
Definitely NOT to the current measuring terminal (Amps).
Yes that's OK. The 250V AC setting will be fine.
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