Three way valve replaced- RCD tripping

[Aandrew]

Plumber and electrician came round to replace our three way valve on Thursday. When they went to turn back on the central heating at the fused switch in the kitchen the RCD tripped. They said it could be water in the wiring somewhere as they didnt drain the system first despite them putting a load of towels down some water did leak out. Five days later though and its still tripping every time I try and turn the central heating on.

They are trying to tell me its a fault under the floorboards somewhere and want to start pulling them up which Im not having at all. We've got big boards rather than floorboards so that would be a nightmare. It wasnt tripping before they got here, so its something they have done.

Can a faulty or incorrectly wired three way valve cause this sort of thing? They have apparently tested everything but I refuse to believe that this is just a coincidence and that the fault lies elsewhere.

I have some photos of the wiring if thats of any use?

 

[seco services]

why was it replaced ?
did they change complete valve or just the actuator ? (top part)

sounds like it maybe wired wrong.

 

[JohnD]

or maybe it is done correctly and the old one was wrong?

Does the boiler heat the hot water cylinder OK?

a proper electrician should be able to disconnect the load and see if the fault is still present on the wiring. Has he done that yet? If so, then he is probably right.

 

[Agile]

There seems to be significant problems with the skills level of both of these people.

A competent heating engineer or even most plumbers would have no problem fitting a motor valve themselves without needing an electrician.

Any competent electrician would be able to find the cause, or at the very least, the circuit causing the problem.

As usual I wonder about who has been paid what!

In a normal situation, I would say that they should sort out the problem but as they think they need to take up floorboards you dont want that.

Perhaps its time to call a competent heating engineer with the skill to find electrical faults.

We would charge about £192 to supply and fit a new three port valve located upstairs if access was available to the feed tank. A bit less if a sealed system. But we would accept full responsibility for leaving a working system.

Tony

 

[Aandrew]

Well the original problem was that the radiators were heating up when the hot water was on (central heating off). The solenoid part of the three way valve had previously failed and been replaced, it was assumed that it was the other remaining part that had failed this time. It would have been about ten years old.

In the kitchen we have the central heating timer/control and next to it the fused switch which controls the power. The RCD trips as soon as I turn the fused switch on, the timer/control doesnt have the chance to demand any hot water from the boiler.

The biggest problem in all this is that my wife got her sisters boyfriend to attempt the replacement as a favour. He replaced the part, his electrician friend wired it up. As much as I think they are at fault for this, my wife is having none of it, which is more to do with not making waves with her sister as anything.

 

[Aandrew]

or maybe it is done correctly and the old one was wrong?

Does the boiler heat the hot water cylinder OK?

a proper electrician should be able to disconnect the load and see if the fault is still present on the wiring. Has he done that yet? If so, then he is probably right.

I wasnt here at the time but according to my wife he tested it all and couldnt find anything wrong. Im no electrician but I would have thought if there was any kind of fault in the wiring then he should be able to find something??

 

[seco services]

wheres the pic's ?

many elecys can't wire heating controls.

 

[Aandrew]

Sorry about the quality, the black cable leads to the new valve, it all makes no sense to me.

 

[electronicsuk]

I wasnt here at the time but according to my wife he tested it all and couldnt find anything wrong. Im no electrician but I would have thought if there was any kind of fault in the wiring then he should be able to find something??

If the fault isn't intermittent and it's clear that the CH is the problem, it should be pretty easy for your electrician to perform an insulation resistance test on certain parts of the system in isolation. He wont be able to perform such a test on any sensitive electronic parts such as a digital timeclock, but it wont do any harm to the valves or thermostats. By testing between L/N and E it should become clear if any part of the system is at fault.

Oh, and the wiring inside that JB is messy to say the least - if it was done by the spark then he should be ashamed. Why in the world is there a green/yellow flex jointing onto a orange flex? Looks wrong to me already...

 

[Aandrew]

A couple more ..

 

[seco services]

whats the two white cable go to ?

 

[Aandrew]

I wasnt here at the time but according to my wife he tested it all and couldnt find anything wrong. Im no electrician but I would have thought if there was any kind of fault in the wiring then he should be able to find something??

If the fault isn't intermittent and it's clear that the CH is the problem, it should be pretty easy for your electrician to perform an insulation resistance test on certain parts of the system in isolation. He wont be able to perform such a test on any sensitive electronic parts such as a digital timeclock, but it wont do any harm to the valves or thermostats. By testing between L/N and E it should become clear if any part of the system is at fault.

Oh, and the wiring inside that JB is messy to say the least - if it was done by the spark then he should be ashamed. Why in the world is there a green/yellow flex jointing onto a orange flex? Looks wrong to me already...

Exactly the point Im trying to make to my wife, the problem is 100% reproducable. I dont for one minute believe the only way we can find out whats wrong is to start pulling floors up.

 

[Aandrew]

whats the two white cable go to ?

One goes to the water pump, the other to the thermostat on the hot water tank.

 

[seco services]

the orange wire in the box joins a y/g wire that looks like it gos to one of them white cables. what is the white cable feeding pump/cyl stat ?

 

[Aandrew]

the orange wire in the box joins a y/g wire that looks like it gos to one of them white cables. what is the white cable feeding pump/cyl stat ?

The yellow/green cable is from the water tank thermostat, the other wires coming from the same cable are the blue and brown wires on the far right of the same block.