Immersion Heater fault

[mallard63]

I have posted this one in the plumbs forum and was advised to get 2nd opinions here.
The immersion heater blew its switch fuse. I replaced this and it works for about an hour before blowing again.
Could a faulty thermostat cause this? the area where the element goes into the cylinder (top) had quite a build up of scale which was rubbed down.

 

[Taylortwocities]

Probably the element has a fault. get a spark to do an insulation test on it.

If its crook you'll need a plumber to drain the tank and put in a new one.