electic shower

[theaims]

we are planning to put in an electric shower over the bath in a block of flats 20th floor. the flat 3 floors dows says his shower gets to one bar. is it worth putting it in will the pressure be enough and what is the most powerfull electric shower out at the moment thanks

 

[breezer]

the question is, have you got a spare "fuse" to connect it to on your consumers unit? if not time for new consumers unit, oh, and shower curtain, shower curtain rail shower pole etc etc

 

[Kimba]

1 bar is usualy plenty, although if your water is fed from a roof tank, you may have the option of fitting a pump to increase the flow rate (DON'T DO THIS IF IT'S DIRECTLY WATER MAINS FED)

Most electric showers are in the 9-10kw range, which give ample temperature for a decent flow rate, there are some as powerful as 14kw, but your electric bill with rocket. Assuming a 10Kw unit is used, you need a 40Amp breaker/fuse from the consumer unit, and it should be protected by an RCD (either an extenally added two way consumer unit, or a built in one if you have a new unit.

Bare in mind if the run from the consumer unit to the shower is much more than a few metres, you will need to use some pretty heafty size cabling. There are lots of rules with regards to having a double pole pull cord just outside of zone 1, and a double check non-return value fitting on the cold supply to the shower unit, but these should be detailed in the instruction manual.

 

[ban-all-sheds]

40A is a bit light for a 10kW shower.

10000/240 = 41.7

10000/230 = 43.5

 

[securespark]

Never seen anything as heavy as 14.

From what I have seen, 50A is the max. The DP switches (domestic anyway) don't get higher than 50A.

 

[ban-all-sheds]

Never seen anything as heavy as 14..

I'll bet they're on their way....

 

[Kimba]

Sorry 50A would be better, was thinking 9.5 at the time

You can get 14s now, but tend to be for commercial installations.

 

[jonno]

Interesting to read all your comments - if I was to step up to a 10.5kW shower from my 9.5kW could I re-use the existing 45A or would I be better stepping up to 50A

 

[ban-all-sheds]

Interesting to read all your comments - if I was to step up to a 10.5kW shower from my 9.5kW could I re-use the existing 45A or would I be better stepping up to 50A

1) Can you divide 10500 by 230? (and then add on 10% which is what the supply voltage could increase by)

2) But before that comes another step - what size cable supplies the shower?

 

[jonno]

That's why I asked the question, as I was led to believe cable size had a bearing , the existing cable is 10mm

 

[Big_Spark]

That's why I asked the question, as I was led to believe cable size had a bearing , the existing cable is 10mm

Jonno, as the others are answering your questions, I have one for you, and PLEASE do not take this the wrong way.

You say your flat is 20th floor, may I ask if this is a council/housing association property?

The reason I ask is simply to advise you that if it is I would check your tenancy agreement, some will not allow you to undertake this work yourself, they would want to see paperwork from a contractor to prove they installed and tested the kit.

This may not be the case for you, all authorities and associations are different, but many do ban DIY electrical and plumbing work in their properties.

 

[ban-all-sheds]

Actually it wasn't Jonno on the 20th floor, but your point is very well made.

As for Jonno - your 10mm will probably be fine for a 10.5kW shower - do you know where it runs on its journey from the consumer unit to the shower?

 

[jonno]

Not exactly - it appears to run from the consumer unit downstairs, up and under the floor on the landing across to bathroom and up wall cavity into loft to pull switch and back to shower unit, approx. 8-10 metres to switch and 2m back to shower unit, to be honest if it means upgrading cable and fuses to change to 10.5kW I'll just get a new 9.5kW, the old one was ok and still is in the summer but now struggles to heat the water sufficiently in colder weather.

 

[theaims]

thanks everyone for youre comments.

 

[ban-all-sheds]

Not exactly - it appears to run from the consumer unit downstairs, up and under the floor on the landing across to bathroom and up wall cavity into loft to pull switch and back to shower unit, approx. 8-10 metres to switch and 2m back to shower unit, to be honest if it means upgrading cable and fuses to change to 10.5kW I'll just get a new 9.5kW, the old one was ok and still is in the summer but now struggles to heat the water sufficiently in colder weather.

Voltage drop is no problem for that length of 10mm. Perhaps some kind soul with cable calc s/w on his PC will run a few scenarios with different grouping factors to see if problems are likely. Is the cable in insulation at any point, e.g. in the wall, or in the loft?