My immersion heater for the water is controlled by a plug and socket in the hall way. I've noticed the plug/socket gets hot if I leave it turned on for a long period of time ie have a shower and forget to unplug for the rest of the day.

Is this normal/dangerous?

Bobbins, January 2008

By current standards and Good practice An immersion heater should have its own circuit, As said on normal 240volt the 3Kw Element takes 13A but if you have a local volt drop and end up with less volts The Current drawn will be higher, In practice a 13A DP Fused spur will only have the same effect as the plug It will get hot and bothered and could possible cause a fire, but a fuse spur is in the wall and If its a stud wall the effects could be far worse, Hense a seperate circuit with a 16A Breaker With 2.5 Twin & Earth To a 20A Double Pole Switch And a 2.5mm Heat Resistant Flex Between the Element Connections and The said Unit, the current method Could be causing/have caused damaged to the cables connected to the socket, Basically Leave it alone and get the whole thing checked by a Approved Electrician, (usually one in your local pub)

Dodge, January 2008

yes it is potentially dangerous.
the problem is likely to be......
1. loose wiring connection within the plug,
2. loose wiring connection within the socket,
3. undersised or unsuitable water heater wiring,
4. or combinations of the above.
the appliance should be permenantly connected via
a 13 amp connection unit. this needs attention by an Electrician, and soon.

mike, January 2008

Its unusual for an immersion heater to be controlled this way- a 3kw heater takes a full 13 amps of current and this is at the upper end limit of any standard plug and socket. This is why these things should be hard wired, using a 30 amp double pole switch outlet. I wouldn't be very happy using your method, and it certainly wouldn't pass todays wiring recommendations.

John, January 2008