Power Shower Question

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Discussion

N10k

Original Poster:

5,094 posts

235 months

Sunday 9th January 2011
quotequote all
Hi,
Im looking at replacing my power shower. Looking at it i can only see one feed going into it, it looks like just a cold water feed.

Is it common to have a power shower just running off a cold feed?

Can anyone recommend me a power shower which only needs a cold feed.

Thanks
Nick

garycat

4,400 posts

210 months

Sunday 9th January 2011
quotequote all
All power showers are just a cold feed. The water is heated by the shower unit. Make sure the cable is thick enough for the kW rating of your new shower, it should be at least 6mm or even 10mm and connected directly to the consumer unit.

B17NNS

18,506 posts

247 months

Monday 10th January 2011
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Sounds like you have an electric shower not a power shower.

An electric shower has just a cold feed from the mains and the water is heated on demand by electricity.

A power shower is a 'pumped' shower and uses water from the hot and cold tanks.

Power showers can look like an electric shower (the pump is in the shower unit) or you could have a regular theromstatic valve in the bathroom with a seperate pump usually located in the airing cupboard.

An electric shower is powered usually by a 10mm cable directly from the board.

A power shower (or pumped shower) can be supplied by a regular 13a spur or socket.

Power shower (hot and cold tank fed):
http://www.screwfix.com/prods/66237/Bathrooms-Show...

Electric Shower (cold mains fed):
http://www.screwfix.com/prods/88963/Bathrooms-Show...

Edited by B17NNS on Monday 10th January 00:26

Griff Boy

1,563 posts

231 months

Monday 10th January 2011
quotequote all
garycat said:
All power showers are just a cold feed. The water is heated by the shower unit. Make sure the cable is thick enough for the kW rating of your new shower, it should be at least 6mm or even 10mm and connected directly to the consumer unit.
Sorry to disagree here, but power showers definetely do not run off a cold supy only. They require a hot and cold, and either contain a small pump within the unit ( normal/industry definetion of a power shower) or are fed by a pumped, balanced hot and cold water supply. (common term for a power shower)

Showers with only a cold water feed are always electric.

Sixpackpert

4,558 posts

214 months

Monday 10th January 2011
quotequote all
Griff Boy said:
garycat said:
All power showers are just a cold feed. The water is heated by the shower unit. Make sure the cable is thick enough for the kW rating of your new shower, it should be at least 6mm or even 10mm and connected directly to the consumer unit.
Sorry to disagree here, but power showers definetely do not run off a cold supy only. They require a hot and cold, and either contain a small pump within the unit ( normal/industry definetion of a power shower) or are fed by a pumped, balanced hot and cold water supply. (common term for a power shower)

Showers with only a cold water feed are always electric.
This.

OP, you definitely have an electric shower there.

Road2Ruin

5,212 posts

216 months

Monday 10th January 2011
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I have to agree. If it's only got a cold feed it must be an eletric shower. It may be quite powerful, but it's not a power shower.

DocJock

8,357 posts

240 months

Tuesday 11th January 2011
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You can buy 10Kw electric showers with an integral pump...

N10k

Original Poster:

5,094 posts

235 months

Tuesday 11th January 2011
quotequote all
SO i have an electric shower. Well its rubbish.

Is there an electric shower which can also improve the water pressure?

Electric power shower?
I only have a cold feed though....

What ratings should i be looking at when im checking out showers?

N10k

Original Poster:

5,094 posts

235 months

Tuesday 11th January 2011
quotequote all
http://www.homebase.co.uk/webapp/wcs/stores/servle...
What about this?
What does 9.5kw? is that its power?

Mr Pointy

11,220 posts

159 months

Tuesday 11th January 2011
quotequote all
Do you know how big the cable feeding the shower is (probably 6mm or 10mm) & what size is the fuse it's connected to? This may limit the kW rating of the shower you can fit.

russ_a

4,578 posts

211 months

Tuesday 11th January 2011
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I had a 9.5kw pumped electric shower and it was rubbish!!

N10k

Original Poster:

5,094 posts

235 months

Tuesday 11th January 2011
quotequote all




This is the cable, looks like a 6mm or 8?.

Would i only need to replace the cable from the shower to the shower power cord which is on the ceiling??

Edited by N10k on Tuesday 11th January 15:08

CedGTV

2,538 posts

254 months

Tuesday 11th January 2011
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Cable looks meaty enough, however if you are going to replace it, then it would have to replaced right back to the fuse board.

N10k

Original Poster:

5,094 posts

235 months

Tuesday 11th January 2011
quotequote all
Thanks for the reply. Lets hope i dont have to replace the cable!

Smiler.

11,752 posts

230 months

Tuesday 11th January 2011
quotequote all
I wouldn't put a 9.5kW unit on a 6mm² cable. It is possible with twin & earth under the right installation conditions.

I'd use 10mm².

N10k

Original Poster:

5,094 posts

235 months

Wednesday 12th January 2011
quotequote all
Smiler. said:
I wouldn't put a 9.5kW unit on a 6mm² cable. It is possible with twin & earth under the right installation conditions.

I'd use 10mm².
What size is my cable?
Does it look like 6 or 10mm?

Ganglandboss

8,307 posts

203 months

Wednesday 12th January 2011
quotequote all
N10k said:
Smiler. said:
I wouldn't put a 9.5kW unit on a 6mm² cable. It is possible with twin & earth under the right installation conditions.

I'd use 10mm².
What size is my cable?
Does it look like 6 or 10mm?
That looks like 6mm² but it is difficult to tell from a photograph. Can you see the outer sheath of the cable anywhere (such as where it runs through the loft)? Sometimes the size is stamped on the sheath but it is not always. The easiest way to check is by getting a sample of cable and holding it against it - a small DIY shop who sell cable off the reel will probably give you a sample.

If you do have to upgrade the cable, it is notifiable works under Part P. You will either have to get an approved domestic installer to do it or jump through hoops for building control if you DIY. You can swap the shower for a unit to the same capacity without having to use an approved domestic installer but I urge you to get it checked by somebody competent.

As previously stated, you will need a 10mm² supply for a 9.5 kW shower. A 6mm² supply would be okay in certain circumstances but you need ideal conditions (cable clipped direct to the wall, not buried in the building fabric or thermal insulation, short run) - this is rare in a typical family house.

Re. choosing a new shower, I have never had any trouble with Mira other than an O-ring failing on a unit that was about 10 years old. Mira sent a seal kit in the post free of charge. Go for the highest rating your cable can handle (get somebody competent to tell you this - they will have to inspect the cable run to verify a number of factors as the installation method affects the current carrying capacity of the cable). The higher the rating, the faster it will heat water meaning you can get a greater flow.



Edited by Ganglandboss on Wednesday 12th January 14:25

garycat

4,400 posts

210 months

Wednesday 12th January 2011
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6mm and 10mm cable should have ~7 strands per core like this

http://www.screwfix.com/prods/73076/Electrical-Sup...