Electrical fault

[baz]

Why does the neutral wire in my electric shower (8.5kw) keep overheating and melting the connecting block?

[O.B.]

If its happening right at the connection point then it must be higher resistance there. So the connection isn't being made properly or tight enough or the connecting block is no good.

[O.B.]

If its happening right at the connection point then it must be higher resistance there. So the connection isn't being made properly or tight enough or the connecting block is no good.

[Christian McArdle]

Bad connection, probably because the screw terminal came loose. If the connection has gone wrong before, then the terminals themselves will be covered in carbon and make it difficult to make a good connection in the future. This is assuming, of course, that the appropriate size cable has been used.

Christian.

[Andrew Gabriel]

Another possibility is a fault in the shower with it making a bad internal connection to the terminal, resulting in overheating being conducted back through the terminal to the cable. This could have been caused by a poor cable connection initially, which damaged the shower internal connection.