Mixer tap showers - advice required

[goosander]

I would like to fit a shower over my bath, the easiest way would be to replace the bath taps with a mixer tap that has a shower attachment but I'm not sure if that would work with my plumbing.

The hot water to the bath is from a HW tank fed from a cold water tank in the loft whereas the cold supply is mains pressure. Will I need to reduce the pressure of the cold water supply to the shower, or is a mixer tap simply not suitable?

Are these mixer tap showers any good, or should I just consider going for an electric shower.

 

[swidders]

Not really suitable. Possibly electric.

Better to get a pump or power shower installed - these will give you a superior flow rate but will require more plumbing work.

 

[Softus]

the easiest way...

What criteria are you using to decide on the type of shower?

Hint: easiest to install is not a good way of deciding.

 

[goosander]

Criteria are cost & ease of install. The shower won't be the main shower in the house, so it just needs to be adequate rather than excellent.

I don't want to spend more than about £200 and would rather not have to dig holes in the wall or re-tile the bathroom for the plumbing hence the mixer tap shower idea.

Second choice would probably be an electric shower as there is easy access to mains cold water from above or below, so I would plan on running exposed pipework rather than hiding it in the wall.

 

[swidders]

Fair enough - just the electrician to pay then.

 

[goosander]

I assume that was a reference to Part P?

I had been planning to do the electrics myself as well (to hell with Part P) - Although not a sparkie, I have an electrical engineering background and access to the current wiring regs, so am confident of being able to do a proper job.

 

[Softus]

Criteria are cost...

OK.

...& ease of install.

Will you be installing it, or will it be someone who's used to doing this kind of work?

The shower won't be the main shower in the house, so it just needs to be adequate rather than excellent.

In that case an electric shower will just scrape by on that criterion...

I don't want to spend more than about £200

...but not that one.

Second choice would probably be an electric shower as there is easy access to mains cold water from above or below, so I would plan on running exposed pipework rather than hiding it in the wall.

A half-decent unit will cost around £150, and the plumbing work/parts around £100. The electrical work could easily be as much as £300, IF your existing consumer unit supports it. Otherwise you're looking at spending around £300 on a valve and riser kit, and about £200 on plumbing, and that's without a pump or, if necessary, equalising valve. If you have unbalanced supplies then you could/should fit a Trevi Boost. Can't remember how much they cost.

 

[Softus]

I assume that was a reference to Part P?

No.

I had been planning to do the electrics myself as well (to hell with Part P) - Although not a sparkie

Hmm.

I have an electrical engineering background and access to the current wiring regs, so am confident of being able to do a proper job.

OK then. How will you calculate the correct cable CSA to use?

 

[swidders]

I assume that was a reference to Part P?

I had been planning to do the electrics myself as well (to hell with Part P) - Although not a sparkie, I have an electrical engineering background and access to the current wiring regs, so am confident of being able to do a proper job.

First of all - Softus is correct in his analysis and you should take it on board.

Regardless of whether you think you are competent, wiring in special areas (such as bathrooms/kitchens) by unqualified persons are not permissable by law. You may wish to put a related post on the electric forum to clarify this.

Apart from anything else, you automatically invalidate the warranty of your electric shower

 

[Softus]

Regardless of whether you think you are competent, wiring in special areas (such as bathrooms/kitchens) by unqualified persons are not permissable by law.

Sorry to be the one to tell you swidders, but you're wrong.

The Building Regulations require that the installation be safe - no qualifications are needed to support this, but knowledge is and skills are.

However, notification is also a legal requirement, so ignoring Part P when notification is required is a summary offence.

Apart from anything else, you automatically invalidate the warranty of your electric shower

I doubt that the installer being qualified is a condition of purchase. Clearly the manufacturer will advocate it, but that's not the same thing.

 

[swidders]

Regardless of whether you think you are competent, wiring in special areas (such as bathrooms/kitchens) by unqualified persons are not permissable by law.

Sorry to be the one to tell you swidders, but you're wrong.

Always happy(?) to be corrected when factually in error

The Building Regulations require that the installation be safe - no qualifications are needed to support this, but knowledge is and skills are.

However, notification is also a legal requirement, so ignoring Part P when notification is required is a summary offence.

To the op - this will more than likely cost more than hiring an electrician since building control will want to inspect

Apart from anything else, you automatically invalidate the warranty of your electric shower

I doubt that the installer being qualified is a condition of purchase. Clearly the manufacturer will advocate it, but that's not the same thing.

True, but the instructions will almost certainly state "this appliance must only be installed by a qualified electrician" or similar, in which case, failure to do so will be in breach of the MI's, the outcome of this (most probably) being stated elsewhere as per norm.

 

[goosander]

I live in Scotland so Part P doesn't apply. Last time I looked in to it, Scotland hadn't adopted a Part P equivalent but thats probably changed by now - must check.

 

[Softus]

True, but the instructions will almost certainly state "this appliance must only be installed by a qualified electrician" or similar...

I agree.

...in which case, failure to do so will be in breach of the MI's

Without wishing to be picky, I would say that it contravenes the MIs, but not in a way that would invalidate the warranty.

the outcome of this (most probably) being stated elsewhere as per norm.

Not sure what you meant by this bit.

 

[Softus]

I live in Scotland so Part P doesn't apply.

In that case why did you write "to hell with Part P"?

Last time I looked in to it, Scotland hadn't adopted a Part P equivalent but thats probably changed by now - must check.

You still have electrical fires though, right?

To reiterate: how will you calculate the correct cable CSA to use?

 

[swidders]

True, but the instructions will almost certainly state "this appliance must only be installed by a qualified electrician" or similar...

I agree.

Checked a MI - confirmed

...in which case, failure to do so will be in breach of the MI's

Without wishing to be picky, I would say that it contravenes the MIs, but not in a way that would invalidate the warranty.

the outcome of this (most probably) being stated elsewhere as per norm.

Not sure what you meant by this bit.

From (my sample of 1) MI :

"Not covered by this guarantee - Damage or defects arising from incorrect installation"

I would argue that failure to be installed by a qualified electrician semantically means that it is prima facie an incorrect installation