Maximum KW Shower on current set up - pics included

[borofc]

I'm intending to finally refit my bathroom, first thing I want to get sorted before I start removing tiles and making a mess is the maximum KW shower I can currently install and what are my options as my current shower suggests my electrics may not be suitable for modern showers.

6mm cable

The cable from the back of my shower covers the following distance to the fuse box

0.5m though the wall up from the shower to the ceiling
4.6m in trunking along the hallway towards fuse box
2.9m inside wall to reach fuse box

As my fuse box is quite old someone suggested a good option would be to get purchase 40A MCB, enabling me to install a modern 8.5+ KW shower?

Anyway all help is appreciated, thanks in advance

 

[overskilled]

Is the RCD for the shower after the MCB?
Current carrying capacity for the cable depends on several factors - including but not limited to: is it grouped with other cables? is it covered with insulation and if so how deep and for how far of its run? Water pressure is another point

I'd advise talking to a spark who fits showers and get some advice, you may find its a lot less hassle getting someone in. I'd advise at a minimum getting the cabling IR and continuity tested and the RCD tested to ensure that it is still operating correctly, you may find it difficult getting breakers for that board, I'm not 100% which model of crabtree that is....

 

[Des 56]

Rather than a new unit for a shower,if there are to be alterations,you should consider having the existing consumer unit renewed,you have no Rcd protection of your installation for the circuits other than the shower

The Redring super 7x was an excellent shower by the way

You certainly should not install larger than 8.5KW using the current 6.0mm cable

The probability is that your shower isolator would also require upgrading,it may only be 30amp rated and no doubt well used also

The Crabtree 40 amp Type 1 Mcbs are still available by the way

You are best to get an electrician involved or stick with 7 or 8 Kw replacement unit

The larger rated showers are on the whole a waste of time and effort,for little if no benefit
In the meantime,you could renovate your Bathroom and make provision for future use by installing a piece of 10mm from the shower position to the Pull cord and crack on with the alterations