Water Heater Wiring

[Dave11953]

I am putting in a 9.5kW Sirrus Quickstart Undersink water heater in my kitchen. It will only serve the washing up bowl and for hand washing (no washing machine or dishwasher) but I was told to use a 9.5kw because it is attached to a mixer tap.

The cable run is about 9m from the consumer unit to the isolating switch (45A DP), and I am using 10mm cable (surface mounted on the wall behind kitchen units) with a 32A fuse. The isolating switch is about 1.5m from the water heater.

My question is … is it ok to run 6mm cable from the switch to the heater? It is getting very crowded at the back of the switch and trying to squeeze two 10mm cables (load and feed) into the available space just doesn't seem right and is VERY difficult.

Thanks

 

[RF Lighting]

Are you using the correct sized back box for switch?

You should have a deep box when using cable of this size

 

[Spark123]

Your 32A fuse is a bit on the small size too, needs to be 40A.
Please note this work is notifiable to your Local Area Building Control under Part P of the building regs.

 

[Paper Spark]

I am putting in a 9.5kW Sirrus Quickstart Undersink water heater in my kitchen.

The cable run is about 9m from the consumer unit to the isolating switch (45A DP), and I am using 10mm cable (surface mounted on the wall behind kitchen units) with a 32A fuse.

9.5Kw @ 230V = 41.3A

So 6.00mm cable won't carry this load, it'll have to be 10.00mm all the way. And as RF has already said you'll need a deep box for the switch.

 

[Dave11953]

Thanks for the quick and helpful replies.