Immersion Heater

[derekw]

Just moved into a new flat where the immersion tank is not wired up to a switch. Instead the immersion tank is connected to a plug, to get hot water we put in the plug and switch on at the socket.

We have noticed that the plug tends to overheat with burn marks around the base of the Live connection. The fuse burnt out about two weeks after this and I replaced the fuse and contacted a sparks. The sparks just replaced the thermostat, but the problem has come back. The plug is now overheating on a daily basis.

The connections in the plug are brown - Live, green - Earth and black - neutral, the blue wire has been severed.

Can anyone advise as to how the plug is overheating? I don't think the thermostat is at fault as the water coming from the faucets is not scalding hot.

 

[bernardgreen]

Plug and /or socket is over loaded.

Is it a "13 amp" socket ? MAXIMUM load for that type is 13 amps but not all makes of plugs are capapable of running at 13 amps as the clips that hold the fuse do not make a good enough contact with the fuse and a heat is produced. One large industrial user derated use of 13 amp plug to a maximum of 9 amps with exceptions for special use where only one make was permitted.

If there is scorching on the socket the electrician should have replaced that. If the water was getting hot and was about the right temperature then the thermostat was OK and didn't need replacing.

A double pole fused outlet with the cable from the heater permanently wired is the prefered method.

 

[JohnD]

the plug and the socket will both be damaged by the heat and should have been replaced. If either plug or socket are worn and loose they are more prone to overheating due to poor contact. Good brands are MK, MEM and Crabtree.

A single socket has the advantage that the load on it will not be increased by having two appliances running at the same time as can happen with a double socket.

A dedicated radial circuit fused at 16A with a DP switch is the correct way to install an imersion heater.

If there is a problem doing this, change the plug and socket for a switched fused connection unit with flex outlet.

Is this a rented property?

 

[bengasman]

The wires are brown and BLACK? The blue wire cut? Sounds very odd, is this hard wire or flex? How many cables are coming together? Standard immersion element should run fine form a plug, provided the wiring goes in whole and is tightened correctly. What is the capacity of the element?