electric shower

[Mark Edney]

Hi Guys
I have a full bathroom replacement to do and customer wants his electric shower replacing.
Do i have to be part p to change shower?
If replacing an electric shower of the same wattage for a customer does the wiring/earth need to be changed and if so what needs changing?

Cheers for your impending help

Mark

 

[AWheating]

is the cable the correct size? is the protective device the correct type and size?

 

[Paulus]

Strictly speaking, yes you should be part P qualified. Having said that I believe most plumbers would just get on with it if it's a straight swap and no wiring needs changing. At the end of the day it's only like wiring a plug.

When I do one I always give the customer the option of getting an electrician in.

 

[Mark Edney]

cheers paulus will do just that!!

 

[secret squirrel]

I don't think you need to be part p for a straight swap, you only need to be part p to do an install from scratch!

If you needed to be part p for a straight swap would you then need to be part p to wire a pump in or a 2/3 port valve if its a swap

 

[gravytrain]

so long as they are not upgrading the shower to a higher power rating you'll be fine
check that the new shower will retro fit the old supplies, so the water and elec are on the same side or its
a make designed to retro fit other models
check the condition of the old wiring if it looks like its been heat damaged the get in a sparky quick

if there isnt a separate supply with a separate fuse/rcd then also get in a sparky.

 

[AWheating]

the difference is that the pump or 2/3 port valve is normally not fitted in a bathroom which i think is classed as a special location. My personal opinion is if you understand and can check the basic circuit is suitable then i would just swap it yourself. Hence the reasons i asked the questions on cable size etc.... if you dont understand the need to ensure these things are correct then ask an electrician to do the work.

I have seen the aftermouth of what an undersized cable can do connected to a shower. Once the fire was out!

 

[Mark Edney]

Not sure about cable size or protective device.....reckon i will get a sparky in to suss the job out

thanks

 

[Mark Edney]

is it right the earth has to be 16mm and if so is this on new install or replacement, seems unneccesary to change the earth wire if its done its job upto now?

 

[secret squirrel]

the difference is that the pump or 2/3 port valve is normally not fitted in a bathroom which i think is classed as a special location. My personal opinion is if you understand and can check the basic circuit is suitable then i would just swap it yourself. Hence the reasons i asked the questions on cable size etc.... if you dont understand the need to ensure these things are correct then ask an electrician to do the work.

I have seen the aftermouth of what an undersized cable can do connected to a shower. Once the fire was out!

Not a critism, just a different view.

If someone can give a definetive yes you need a sparks, I'll be happy but I'm almost sure regs don't require it.

Yes your correct bathrooms are a special area and showers should be rcd protected

 

[AWheating]

the worst thing you would want to see is it wired to a rewireable fuse board. These can take up to 5secs of fault current (dependant on the current)before dissconecting the supply if my memory is working. not great if the fault current is traveling through a person at the time.

 

[AWheating]

Not a critism, just a different view.

If someone can give a definetive yes you need a sparks, I'll be happy but I'm almost sure regs don't require it.

Yes your correct bathrooms are a special area and showers should be rcd protected

just had a read of part p. It is ok to straight swap a shower as long as you dont alter the circuit and it does not need to be notified/cert issued.

i gues the question is although it does not need to be notified does the person fitting the shower need to be competent? im guessing in the eyes of the law yes.

I would be happy that an experienced plumber with electrical knowledge would be. How one proves this tho?

 

[kirkgas]

like everything else, its ok doing a straight swap, IF the original install is correct, thats where the competance bit comes in for me, knowing the original install is ok is the hard bit, its ok saying im changing a 9kw shower and its a 9kw coming out, but if the original cable should be 10mm2 but was put in using 6mm2 then the new install wont be right

 

[AWheating]

i wonder if plumbing course's cover shower wiring now? trying to remember back 16 plus years on level 2 you only covered immersion heater connection and a plug top. on level 3 you covered basic stuff like ohms law and y/s plan. No cable sizing, no selection of fuse's etc....

 

[AWheating]

is it right the earth has to be 16mm and if so is this on new install or replacement, seems unneccesary to change the earth wire if its done its job upto now?

no, i think your getting confused with the main earth conductor which you would find at your fuse board/meter setup. A cpc is normally smaller than the L/N conductors in domestic circuits as twin and earth cables are used.

 

[kirkgas]

i wonder if plumbing course's cover shower wiring now? trying to remember back 16 plus years on level 2 you only covered immersion heater connection and a plug top. on level 3 you covered basic stuff like ohms law and y/s plan. No cable sizing, no selection of fuse's etc....

from next year apprentices will do electrical work as part of the course, it is very similar to Electricity for Plumbers course that runs now, 99% based around safety and central heating, nothing about showers in it as a bathroom is a special location and (i think ) requires additional testing which requires the full test kit and competance to interpret results

 

[secret squirrel]

Just as a side note is there a difference between.

1. not up to current standard
2. dangerous

For example: a 8.5kw shower wired up to 2.5mm twin and earth with a 45amp fuse in the consumer unit or connect up to a 3 pin socket.

Obviously dangerous and should be disconnected etc. No one would argue this point (hopefully)

If, you look at a shower 8.5 kw wired with the correct cable etc into its of circuit breaker (MCB, bear with me I was running earlier and my brain is fried) but not rcd protected should this be ripped out or altered.

Not to current standard but not dangerous.

My point is we'd be turning a relatively cheap and inexpensive job into one that the customer will not/can't pay for.

The sparky I use who is extremley well qualified has said in the past and made a note on the paperwork,

Not to current standard.

I like most professionals would make recommendations but would want the job

 

[kay-jay]

I swap em myself as long as the following criteria are met.

1) modern consumer unit with rcd protection.

2)there is a working double pole switch present.

3) consumer unit and shower are connected by less than 12 meters of flex.

4) there is no signs of overheated cables.

5) a minimum of 6mm cable is installed.

6) never exceed 9.5 kw for 6mm cable.

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[Paulus]

My concern is not only building regs but the customers household insurance. My understanding is that, if the householder pays someone to do the electrics and then there is a claim on the policy due to poor wiring, the insurance company will not accept it as a valid claim.

It doesn't take much for insurance company's not to cough up the cash.

 

[stani]

Kay-jay,
9.5kw shower should be on 10 mm twin and earth, the 12 metre advice was for 7-8 kw showers .

 

[kay-jay]

That's based on calculations that my spark provided. He says 9.5 fine on 6mm within 12 metres. he does say that distance travelled by current is a factor irrespective of kw rating a bit like our fictional resistance. He says if you apply ohms law the calcs prove what he says.

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[stani]

Morning mate, 1st I'm on a day off what you doing on your comp at this time of the morning lol,
2nd, it is my day off and I can't believe I' m up at this time on my computer and worse, on a plumbing forum. What a sad lad. Lol
Our Sparky came up with exactly the same only that it ends to be 10 mm, suppose they are like gas lads its there own interpretation of the rules.

 

[kay-jay]

Lol. I only got jobs this afternoon. Been a couple of quiet days recently but still just about paying the bills come the end of the week. The joys of self employment......

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[stani]

If I hadn't had these 2 days off I would probably have told my boss to shove it, this gives me a long weekend to calm down. Nice job to start Monday, nice customer, different week.

 

[AWheating]

The route of a cable can have a major effect on its size, so its cant be calculated on length and KW alone. The route will effect a cables ability to stay at safe working temps.