Immersion heater/shower pump socket

[davedasave]

can anyone tell me if it is a good or bad idea to fit a twin 13 amp socket to the immersion heater circuit in the airing cupboard and then fit a 13 amp plug to the immersion heater so i can just plug it in and switch it on when its needed (its hardly ever used) and also run a shower pump off the same socket using a 13 amp plug again???

some useful info:
immersion heater circuit is on a 16amp mcb NOT connected to the rcd side of the consumer unit. and the airing cupboard is in the bathroom
the socket also has a fused spur coming out of it to run the central heating timer/thermostat and presumably boiler

Thanks to anyone who can offer me their help and opinions

 

[kai]

You state you have a 16amp MCB breaker feeding the circuit.

The correct and safe way to do it is to have two fused spurs side by side, one fused at 13amp for the immerson heater (max 3kW), and alongside it, another fused spur with a 3amp fuse in it for the shower pump (max 700watts). Diversity is NOT allowed on an immersion circuit, but the 13 plus 3 amp feeds, add up to exactly 16amps, without any diversity, so it complies with regs. Ensure earth bonding is carried out accordingly,

 

[securespark]

Some shower pumps are 5A...

 

[davedasave]

so just to clarify, remove the socket and fit a fused spur at 13amp then spur off that with a 3amp? what about the fused spur for the central heating?

 

[Taylortwocities]

Water heaters over a certain size (15litres I think) are supposed to be on their own dedicated supply.

In the real world this doesnt happen too much. you could consider the feed to the immersion as a radial and design the loads accordingly.
if the cable from the consumer unit is 2.5mm then contact breaker could be raised to 20A, subject to adequate tests being made to confirm EFLI, etc.

 

[Pensdown]

I tend to agree with TCC. Although the regs say they should be on their own circuit, most are now connected to the central heating so the circuit sits there un-used for most of the year.

In worst case you wont be using the shower pump until the water is hot anyway so the overlap time with them both on should only be a few minutes towards the end of your shower

 

[bengasman]

As the airing cupboard is in the bathroom, does that not mean the socket will therefore be in the bathroom?

 

[davedasave]

would it be best to do away with the immersion heater? i don't really need it unless the central heating boiler packs up so should i just use the socket to connect the shower pump to? the cable is 2.5mm t&e

the socket is in the airing cupboard which is in the bathroom

 

[bengasman]

No sockets allowed in bathroom

 

[davedasave]

whats the best solution then? remove socket and replace with 13amp fcu for immersion then spur off that for shower pump then spur off that for central heating? thanks for all the help so far guys

 

[Taylortwocities]

It is a radial circuit so you dont have spurs. Spurs are single cable additions to ring final circuits.

 

[Pensdown]

One side for the immersion FCU the other for the shower pump FCU, both fed from the existing 16amp radial circuit

 

[davedasave]

whats that box called? i can't find one anywhere, or can i just use 3 1 gang boxes side by side for immersion shower and central heating?

 

[Taylortwocities]

Here's where: http://www.tlc-direct.co.uk/Products/GU9D25.html