Shower pump and immersion heater

[jono5000]

Hi all

Just looking for advice. I've had an electrician do a bit of wiring for me including updating fuseboard, replacing switch for immersion heater with 24hr timer, wiring in a spur for shower pump and point and points for shaver socket in bathroom.

The immersion heater is my only source of hot water and located in the airing cupboard next door to the bathroom. The electrician has put a fused timer for the immersion heater and adjacent to that a fused switch for pump (sharing the IH supply?) The wire then goes out of that up to another switch for shaver point and terminates the other side of the wall in the bathroom.

The immersion is then connected to the fuse board RCD protected.

There is a 13amp fuse in the timer switch for IH and another 13 amp for shower pump switch. From what I've been reading this sounds a bit dodgey? The electrician is fully certified, listed on NICEIC website etc, but has got me worrying about what to do if wrong.

 

[jj4091]

What have you been reading? As long as he has used correctly sized & protected cable from the CU & the spur for the pump is rated according to the instalation instructions then everything should be ok. You do not give any info on ratings so it is difficult to be precise

 

[jono5000]

From what I can see, he's used the existing wiring from the old fuse box, which was the old style plug in fuse board which has a dedicated immersion heater circuit. The wires that pass from the box are all in metallic sprues embedded in the walls. There is a red and black wire approx 2.5mm cross sectional coming from the circuit board and attached to the switched fused timer which connects the immersion heater. There are 2.5mm green/yellow cables going off in another direction. There is a new piece of wire added by the electrician, quite a thick grey cable which again contains blue, brown an green cables all 2.5mm thick going to the next switched fuse box for shower pump, which in turn then goes off to another fused switch for shaver socket/light/mirror.

The new CU indicates the immersion heater with an nsb20 switch on the RCD side. Am I right in assuming this is 20amp? If so if the immersion when on draws 13, I get a pump which draws 5, this is ok? and a litle bit left over for a mirror light? And I'm not going to have a problem when I have a shower and the immersion is on.

 

[jono5000]

I have no idea how the pump would connect up. Currently there is a 13amp fuse in the pump switch? Shouldn't there be a 5a? Would a plumber be able to connect a pump to the switch or would I require an electrician?

 

[kai]

The circuit should be perfectly safe, being on the RCD side, off a B20 breaker, provided the shower draws five amps or less, and the immersion is thirteen amps or less - I see no problem in that arrangement.