switch for water heater.

[jackal79]

Hi I had a water tank fitted last year its on economy 7 with 3kw immersion heater running on 13amp switch have noticed switch has started to get hot and melt have changed it for new one but that gets warm on the fuse cover do I need to change the type of switch.

 

[ericmark]

All fuses get hot that's how they work the fused connection unit should be able to dissipate that heat. I have seen it where it is mounted in an insulated wall inside a cupboard where clearly it can't dissipate heat but normally there is no problem.

 

[jackal79]

Its a wall mounted switch also its in a room about 2m sq the fuse holder that you push in is burnt and inside the switch is all deformed where the fuse sits and the fuse is discolured on the ends.

 

[OwainDIYer]

It's usually unnecessary to use a fused switch on an economy 7 immersion heater as it should be supplied from a dedicated circuit fused at 15A or 20A.

This will avoid the fuse overheating problem.

Obviously a fuse is required for an immersion heater supplied from a ring final circuit.

 

[Taylortwocities]

If you changed the switch, you must cut the conductors back to bright copper. Otherwise you will still have a high resistance joint, that will again heat up and fail.

 

[flyingsparks]

What make of switch are you using? A good brand like MK or crabtree will cope with the high currents of an immersion element better than a cheapy thing from poundland.

 

[JohnD]

when you say water tank, do you mean a hot water cylinder with an immersion heater?

Is it on its own circuit, or on the socket circuit?