I have an emersion heater that smells when I switch it on. I have had a plumber look at it and they think it is the wiring that is smouldering, thus causing the smell.

I would expect the cause to be a loose connection either in the switch or in the element. I would suggest getting an electrician to have a look and repair/replace the damaged parts. My charges (as a guide) would be £50 labour plus materials.

I have seen this before where it is a fishy smell. It sounds like the switch has a loose connection in it causing a bad connection. It is better to change the spur/switch. We use ones with red indicators. The butyl flex may also need replacing. £80 plus materials. Kind regards Angelo the electrician

the problem is more than likley to be the flexible cable that connects from the switch to the actual heater element, replace the flex with a 2.5 x 3 core heat proof flexible cable.

Do not use the immersion and get an electrician take a look at this asap as a loose connection can result in fire to the cable and the fused spur. Should cost around £75.00 all included.

How old is you immersion heater and cabling with fuse spur it was supped from? First of all need to check the connections, its may become loose over time. Costing depends on what an electrician will find. if its need replacing of any parts cost for labоr may be £25.00-50.00 plus materials. If its bran new job, and smell ask the electrician who installed it to check that, its should cost nothing.

I suggest that you post a job then you will have several quotes that reflect the actual job relative to your location regards Terry.