Shower keeps tripping off

[ban-all-sheds]

I had a 8.5kw shower, which I replaced with a Triton Bezique 9.5kw.

8.5kW is about 35A and 9.5kW is about 40A.

MCBs don't instantly trip as soon as the current goes over their rated value - there's a curve of how fast they must trip for a given overcurrent.

So for a 30A breaker to pass 35A for long enough to have a shower, and to not pass 40A for anywhere near as long is not a surprise.

Why not to use him? Does it sound too cheap or expsensive?

Neither - it's because he gave you a price without coming to take a look. He can have no idea what problems might surface when he comes to replace it, and it's not impossible that there might be problems that would take days to sort out, so for "£350"he's either planning to leave you with a non-working system if things come off the rails, or he's going to ask for more money in circumstances where you don't have the time or the opportunity to get a competitive quote...

 

[Taylortwocities]

When you ask for instant quotes from other sparks perhaps you should get them to read this thread first!

Dont forget you'll need a spark who can self certify and notify his works.
He/she should be listed at www.competentperson.co.uk