Cut through boiler cable next to the watertank.

[colin jesson]

Hi thanks for these posts

I'm so confused

I only put a nick in the blue cable (red blue yellow earth cable)

I was using a hack saw

British gas has been round tonight. Changed the cassette, checked the internal fuse, changed the pump. He tells me to get a rewire as he can't figure out what is wrong.

I've rechecked the cables, there are no other nicks present.

The wiring is as it was so what could I have damaged, how did this trip out.

There is one more cable going up to the bathroom fan isolator, I haven't taken this one out to check as it would be so hard to fish back in and it's not going to the bolier system to my knowledge.

 

[colin jesson]

It's the right cable, blue wireally I nicked

 

[stem]

The photo of the terminals doesn't really help without knowing what each of the wires is connected to at the other end.

Unfortunately, there is no set way of wiring heating systems. The function assigned to each of the terminals, the colour of the wires selected for interconnecting wiring, and even the type of cables used would have been chosen by the installer according their personal preferences and the materials available, meaning every installation is different.

Is it possible that you have damaged the cables buried in the wall? didn't you say that you were cutting near the skirting? Do the cables pass behind it? Maybe the vibration alone caused a problem somewhere else.

From what I can see of the installation though, it looks very poor. I can't see an earth connection to the metal back box earth terminal top left. If that is the case, not only is it a basic electrical requirement and its absence dangerous, but a professional would never have left it like that, so I wonder what the rest is like. Also, there don't seem to be any cable clamps to secure the cables on the left either. Getting it rewired properly would seem to be good advice IMHO.

 

[Echo the husky]

British gas has been round tonight. Changed the cassette, checked the internal fuse, changed the pump. He tells me to get a rewire as he can't figure out what is wrong.

Why did they change things before finding the fault? Why couldn't they find the fault when the installation is in front of them?

 

[colin jesson]

I was cutting using a hack saw blade so minimal vibration?

The BG engineer looked at the wiring and said something funny is going on and can quote a rewire. 3 hours at 90 per hour

It is so strange though as I have pulled the 3 cables out that go to that connector block. Only the one cable had a nick in the side which has been replaced and double checked again in front of the engineer.

 

[John D v2.0]

Did the fuse definitely blow at that moment you cut through? Any burn marks on the hacksaw blade?

I think a rewire is the best option if he's tested the components alone eg boiler. Our heating in the last house I tried to change the thermostat and it kept blowing the fuse, but all the wiring was tiled into the wall. Never did get to the bottom of it, just rewired and put all the controllers in the stairs cupboard.

 

[colin jesson]

Hi

No burns marks on thr cable or hacksaw blade.

I have asked an electricIan from work to take a look as he is local to me. (Hopefully tonight)

Other than the nick in the blue wire all cables look perfect. I pulled them all out again last night for another look.

 

[HERTS P&D]

Are all the connections tight? I've seen it where everything looked ok but found a wire not making a good contact in a connection.
Check and then check again, you may of pulled a wire without knowing. The fault must be a simple one but not found yet.

Andy

 

[colin jesson]

Thank Andy

When the electrician is around we can check this again. I'm confident the connections are good though as I've check and started over a few times now.

All suggestions are appreciated

 

[John D v2.0]

My main suggestion is don't blow 300 quid on a rewire until the boiler has been confirmed to work when powered directly. You don't want to throw 300 on some cables and need to change the PCB afterwards anyway.

 

[colin jesson]

This is a brilliant suggestion.

Should British gas be able to confirm this before recommending a rewire?

 

[John D v2.0]

This is a brilliant suggestion.

Should British gas be able to confirm this before recommending a rewire?

Yes, it's easy to test. As I say, really all the components could be proved individually. This would, either be with a multi meter, or through functional testing.

 

[colin jesson]

Sorry to be asking silly questions.

Could they test to see if it comes out of lockout out mode? I.e. turn on without the red-light. ?

 

[stem]

There are two issues here. One is that the heating isn't working, but even if it was, there is also the issue of the dodgy / dangerous installation shown in the photograph, unearthed exposed metal etc., and that's what can be seen. I would be seriously concerned that whoever did the work has left other undiscovered faults elsewhere, one of which maybe responsible for the current situation.

So, it really ought to be rewired in any case, or at least checked and rectified by a competent electrician. [Note; not all boiler engineers are competent electricians]

John D v2.0 is right though. It wouldn't be difficult for a boiler engineer to check the boiler in isolation from the rest of the wiring.

 

[colin jesson]

I will show the electrician this comment tonight. Ask him to make it safe too

And then maybe a phone call to British gas