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The background to this is that I have a close friend who runs a charity helping to homeless people into work and accommodation. Needless to say the accommodation is usually right at the bottom end of the range. This weekend she asked me to take a look at a studio flat in Reading where a tenant is having trouble with the landlord.

There were varioius issues, but the plumbing part of this is that the flat has a sink in the kitchen and a basin and a bath in the bathroom. Over the bath there's an electric shower. All three of the hot taps are connected to a single Ariston 15 litre electric water heater under the kitchen sink. I looked at the the approved guidance to G3 and it wasn't clear to me that the landlord is obliged to provide any more than this. I guess that 15 litres is sufficient to feed the kitchen sink and the basin. It wouldn't be enough for the bath, but in theory I suppose the electric shower over the bath could be used to provide a continual supply of hot water into the bath.

I've never seen a flat as poorly equipped as this, but I'm not sure that the tenant really has any grounds to get it improved. I hope that I'm missing something. If I am, I'd be very pleased to hear what it is.
 
Unfortunately I do not think you are missing anything. The heater clearly will not fill a bath as you have stated. But they have an electric shower. The heater is more than enough for the basin and sink. Someone else maybe more clues up on this than me. But as I see he has done what he needs to. Unless the shower is broken.
 
Look at it this way, what if the bath was removed, its not a requirement to bath , unless for medical reasons, so they can wash using the shower, just look on the bath as a big shower tray,
 
IMG_2901 - cropped.jpg


But it doesn't get him off the hook for not piping up the PRV outlet...
 
Hahaha
 
I hope he’s capped off that prv, you wouldn’t want a leak ruining the cupboard.
 
He has met his legal obligations as to providing hot water, but you're correct as to the PRV not terminating correctly and needs rectifying. Also this is unvented and should be installed by a G3 qualified engineer. I don't like the push fit joints either!
 
Don’t need to be G3 quelled for them as 15 litter or under. But the install is crap and still has to comply the regs....
 
Don’t need to be G3 quelled for them as 15 litter or under. But the install is crap and still has to comply the regs..
I’m sure we had this before and they changed it about 3 years ago that you DO have to be G3. Sure @ShaunCorbs put a link on to the rules. Might not have been him though.
 
Don’t need to be G3 quelled for them as 15 litter or under. But the install is crap and still has to comply the regs..

Wrong G3 a few years ago changed to include all hot water items eg cylinders undersink water heaters (over and under 15l)
 
As I understand it any unvented under 15l is not notifiable to building control, but still should be G3 qualified as far as I am aware, Could be wrong though. Perhaps someone could clarify this?

Correct
 
I stand corrected! Never personally needed to worry about that is I’m qualled, just remembered being told this explicitly on my course! I guess times have moved on!

Yea think it was changed 3 or 4 years ago
 
Did they not up it to 30ltr and under again don't do them anymore so out of touch with rule change, but it a pain trying to keep up with all the changes a lot they don't even tell us about.
 
Hello All,

I am sure that the previous comments from Members are correct regarding there being no breach of any Regulation that makes this 15 Litre Unvented Hot Water Heater `illegal` [apart from the discharge pipe not existing !] - but I think that it should be.

I would state that the 15 Litre Unvented Hot Water Heater should be classed as `unfit for purpose` because it is connected to a Bath but would not be able to supply enough Hot Water to use it.

I do realise that having an Electric Shower means that the Bathroom complies with Building Regulation G5 regarding that `a Bathroom must be provided that has a Bath or Shower` [my wording].

But even so - the fact that this 15 Litre Unvented Hot Water Heater is connected to the Bath should mean that the Heater should have a large enough capacity to supply a Bath.

I have never given much thought to this type of situation - but there should be a Regulation which stipulates that where a Bath is installed there must be sufficient Hot Water to fill the Bath -whether from Stored Hot Water or from Instantaneous supply / Combi Boiler or Instant Water Heater.

I have done some very quick research of the Building Regulations / the Water Regulations / British Standards and I am almost certain that there IS a `Minimum Hot Water Storage` specification for Dwellings etc. covered in B.S.6700 ?

Unfortunately I cannot find a copy of B.S.6700 on my Computer although I thought that I did have one.

However - here is some Information on this subject from the `NHBC Standards`:

NHBC Standards 2011

Look under `Hot Water`:


There are references to:

`The hot water services shall be adequate for the likely demand and consumption`.

There are details of Minimum Hot Water Storage for a couple of examples of Hot Water demands / Bathroom Installations.

I was not able to Copy & Paste the relevant page into this message - hence the Link to it.

As I was rushing to post this message / reply I have not had time to read every word of the Information from the NHBC Standards / BS6700 so perhaps something will be found or quoted which contradict my comments here ?

I do realise that the `NHBC Standards` are NOT Regulations but what about the B.S. 6700 references / stipulations ?

Does this provide enough `Regulation` to class this 15 Litre Unvented Hot Water Heater as `not fit for purpose` because it does NOT provide this:

`The hot water services shall be adequate for the likely demand and consumption`.

Without being able to check at present I am assuming that as the NHBC have quoted B.S. 6700 there must be the above specification within that British Standard ?

Regards,

Chris

EDIT: I have found out that B.S. 6700 has been withdrawn and is now superseded by BS EN 806 - I will try to look at that Standard IF I can find a PDF version of it online.

Chris
 
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Hello again,

Although as I mentioned previously BS 6700 has now been withdrawn the specifications of that Standard were in place for decades - here are some calculations / specifications for the Minimum Hot Water Storage Capacity from a Cylinder for a `Small / One Bath Dwelling`:

QUOTE FROM BS 6700 2006 + 2009:

The application of this formula to the sizing of hot water cylinders is best illustrated by the following examples, in which figures have been rounded.

Examples of application Case 1. Small dwelling with one bath installed:


Maximum requirement: one bath (60 l at 60 °C plus 40 l cold water) plus 10 l hot water at 60 °C for kitchen use followed by a second bath fill after 25 min. Thus draw-off of 70 l at 60 °C followed after 25 min by 100 l at 40 °C is required, which can be achieved by mixing hot at 60 °C with cold at 10 °C. Firstly assume good stratification, e.g. heating by the top-entry immersion heater.

To heat 60 l from 10 °C to 60 °C using a 3 kW input takes (60 × 50) / (14.3 × 3) = 70 min so the second bath has to be provided from storage. In 25 min the volume of water heated to 60 °C is 14.3 × 3 × 25 ÷ 50 = 21 l.

Therefore the minimum storage capacity to meet requirement is 70 + 60 – 21 = 109 l.

Now assuming good mixing of the stored water, as would occur with heating by a primary coil in an indirect cylinder, the temperature of the stored water immediately after the 70 l draw-off would be {(V – 70) × 60 + 70 × 10} ÷ V, which simplifies to 60 – 3500/V. The formula shows that heating for 25 min at 3 kW will raise the temperature through 3 × 25 × 14.3/V or 1072.5/V . Since a water temperature of at least 40 °C is required to run a second bath: (60 – 3500/V) + (1072.5/V) = 40 (or more) where V = 122 l

Thus for case 1, the minimum sizes of storage vessel are given in Table C.1

END OF QUOTE


I could NOT attach a JPEG image of the Table [C1] I got a Forum Error Message and nearly lost this message.

However as described above - the Table showed that in a Cylinder `with Stratification` [Top mounted 3KW Immersion Heater] the minimum Storage required to adhere to the above specifications was 109 Litres.

It also showed the Minimum Storage for a Cylinder `with Mixing` [Primary Coil Heat source] to adhere to the above specifications was 122 Litres.

Although these calculations are for a Hot Water Cylinder - the `probable usage` / minimum Hot Water Storage quantities are still relevant for a `One Bath Dwelling`.

Sorry that the quoted text above is in a `Block` - if I separated it into paragraphs it would be too long to post.


Regards,

Chris
 
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