Worcester Bosch wires melting

[redd]

Hi

about an hour ago all the lights in my house tripped out. I went to the fuseboard and one switch was down. Flicked it back and it tripped out immediately.

few moments later theres and acrid smell and a little smoke in the room

tracked the smell down to the boiler, took the cover off and was met with this (see photo)

have got someone coming out tonight to look at it. In the meantime have turned the power off.

Any idea what would cause this earth wire to melt?

It’s a Worcester Bosch junior 28, has been in about 8 years without any problems

 

[centralheatking]

cheers, have just done that

When you say ‘very lucky’, I’m guessing we were close to a big bang or fire?

Any idea what would cause this? I’ve had a good look and it’s just that earth wire that’s melted and scorched the plastic casing.

Also, the powers now isolated for the circuit it’s on. Presumably I can keep the gas and water on? (Engineer coming later on)

Well done you are ok now, sit back ...cuppa tea and wait for experienced electrician...do let us know what he says as we like feedback it helps us to learn more. centralheatking

 

[SJB060685]

To answer your question redd yes fires can be caused from faults like this, however the fuse and MCB should protect the system from this. RCD's protect people from a shock and work by detecting an imbalance between phase and neutral current, ie when theres an earth fault like you've just experienced

 

[bacon_sandwich]

yep, leave the breaker off. Burnt out earth wires can be a sign of another fault not related to the boiler.

 

[centralheatking]

yep, leave the breaker off. Burnt out earth wires can be a sign of another fault not related to the boiler.

It would appear that PF can do electrics ....well done all...just goes to show We are the Senior Trade
always knew this anyway did we not ! ? ....centralheatking Is there an Electricians Forum ? yes its under a stone
somewhere but nobody knows where ....chking

 

[SJB060685]

I have a very good understanding of electrics, I like to study it in my spare time but I'm not an electrician and I certainly wouldn't argue with Murdoch or any other qualified person

 

[centralheatking]

I have a very good understanding of electrics, I like to study it in my spare time but I'm not an electrician and I certainly wouldn't argue with Murdoch or any other qualified person

Its always important to know ones limitations ...I do. chking

 

[redd]

Thanks for all your help chaps

will report back with the diagnosis later

 

[bacon_sandwich]

Have a degree in electrical engineering and do frequent the other forum, lol
I tend to only look at ops that are either pure gas or electrical, my best friend is plumber

 

[centralheatking]

Have a degree in electrical engineering and do frequent the other forum, lol
I tend to only look at ops that are either pure gas or electrical, my best friend is plumber

I have a friend who is an Electrician we have had him with us for years...we drink with him
...his name is 'Mad Ian' ..he is quite often 'short on his round' usually never buying me a beer before he slopes off ...but we like and most importantly trust him.......centralheatking

 

[OffshoreGas]

Thanks for all your help chaps

will report back with the diagnosis later

Looks more like a fault for a sparky than a plumber to me.

 

[redd]

Man has been to check the boiler and seems to think it's an electrical fault somewhere on that circuit. the wiring in the fuse box next to the boiler looks a bit dodgy, live and neutral wires both have cuts in them and the earth wire sleeve has melted there too

Electrician coming tomorrow.

Thanks for all the advice on here

 

[SJB060685]

I imagine the ground fault is somewhere inside the boiler somewhere. Lots of places and components where this can happen. I hope this sudden rush of current hasn't damaged any more parts. Might be advisable to have both electrician and engineer there at same time

 

[redd]

We’re back in business!

Looks like it was a plug socket in the kitchen (same circuit as boiler) that was at fault. As the electrician took each socket on the circuit out one by one, this one was all burnt out inside. The live wire had melted onto the earth cable. He says the live wire wasn’t secured in the terminal properly and had just come loose over time.

presumably this had made the earth wire ‘live’?

I’ve no idea why it then went into the cellar and nearly set the boiler on fire, when everything else is fine?


Anyway a couple of new sockets later, plus new fuse and socket fitted to boiler supply and all seems well.

 

[SJB060685]

We’re back in business!

Looks like it was a plug socket in the kitchen (same circuit as boiler) that was at fault. As the electrician took each socket on the circuit out one by one, this one was all burnt out inside. The live wire had melted onto the earth cable. He says the live wire wasn’t secured in the terminal properly and had just come loose over time.

presumably this had made the earth wire ‘live’?

I’ve no idea why it then went into the cellar and nearly set the boiler on fire, when everything else is fine?


Anyway a couple of new sockets later, plus new fuse and socket fitted to boiler supply and all seems well.

If the live was loose then it like he said over time it will work its way out of connector. You are right to a degree, the live wire when comes in contact with the earth creates a circuit back to source, without a resistive load you have a sudden, massive rush of current, this rush of current (over current) generates heat and melts any fuse or trips any MCB, which is what they're supposed to do, protect the system and prevent fires.