Can I upgrade my shower without worrying about the wiring

[limitedknowledge]

I currently have a 7.5kw Mira Sport shower which as of about 30 minutes ago became an ex shower. I have been looking to replace it for a while but 7.5kw showers are not that common and I would prefer a 8.5kw one anyway. I have been told that I may need to change the wiring if I upgrade to an 8.5kw which I'd rather not do. The current (ex) shower is covered by a 30amp fuse and the house is about 10 years old.

Can anyone give me some advice please.

 

[securespark]

What size is the cable? What size is the switch? Have you an RCD?

What size is the main switch on the CU feeding the shower?

If you have 4mm² cable, it will need changing. If you have a 30A switch it will need changing. If you don't have an RCD, your (new) shower manufacturer will most probably recommend one. Your 30A fuse will need replacing with a 40A device. If your board does not have a 100A main switch, then you cannot run any circuits higher than 32A on the board.

Then there are other considerations: is your main fuse, tails and meter rated to 100A?

Have you got MEB's in place? Is your equipotential bonding up to scratch within the bathroom?

 

[Softus]

Have you read this yet: //www.diynot.com/forums/viewtopic.php?p=81696#81696

 

[Steve]

An 8.5kw shower draws 37 amps. yes, you will need to upgrade certain things. That 7.5 shower will have been fitted with 4 or 6mm² cable. While 6mm² wil be sufficient for most installations of 8.5kw showers, it is generally recommended that 10mm² is used in all shower circuits due to upgrade requirements in future. and then you could have a 10.5kw shower - this, you WILL NOT regret.

 

[dal5band]

Could you good people say how you recognise the cable size - I also need to replace an electric shower. My cable is 14mm accross including the sheath with 7 x 1mm wires in each conductor. Is this a 6mm² ?

Perhaps you could say how big the 4 & 10mm² cables are on the outside?

(Yes I have a 40 amp breaker & RCD and new consumer unit).

Thanks