water safety regulations

[triplex]

Hi, hoping you lads can answer me a couple of questions or point me in the right direction to perhaps an advisory/safety body that can.
Q1. my daughter bought a new home in dec 2010, Would i be correct in assuming that there was a reg in force at that time restricting the hot water temp to the bath of 48degrees c. I believe that there is now but was it in force then.
Q2. each morning she has to run the cold tap in the bathroom to run off the warm water that ensues. ,,My concern here is regarding the possible hazard of legionella, or perhaps i am over reacting, what do you think.

 

[lame plumber]

hot pipe is to close to cold, mixer wont warm cold water.

 

[triplex]

Thanks lame plumber for your reply. i will update you on the history by saying the plumbing firm/builders? are an absolute joke, dont have a clue what they are doing. daughters had them back many times all to no avail, hence ive had to step in to try and get her problems sorted. obvious that the cold(probably unlagged) pipe is picking up heat from a c/h pipe, but its not a nice thought having all your floor boards and decor ruined. just for the record i am a time served gas fitter without any plumbing experience. Just in case we dont get any satisfaction from them when they revisit her again i was hoping for back-up from a regulatory body hence my previous post for a point in that direction

 

[tamz]

Thanks lame plumber for your reply. i will update you on the history by saying the plumbing firm/builders? are an absolute joke, dont have a clue what they are doing.

Pretty par for the course these days on new build. They pay peanuts so get monkeys. You do get a few guys who know what their doing but at the rates they are paying they couldn't care less.

Look up part G of the building regs. You can download it for free.

 

[carrpaul]

is the builder part of the N H B C ? or any other body's

 

[tamz]

is the builder part of the N H B C ? or any other body's

NHBC will always side with the builder unless it is a serious muck up usually structural. It is the builders who pay them so they don't bite the hand that feeds them.

 

[carrpaul]

So the main problem is the cold water warm before getting cold what type of system has she in there , dose the pipe still get worm when boiler is of , do you know if plastic pipe work is in the house , have they said how long fix will take? Just let them get on with the fix builder will pay for for all making good then the plumber how done the job will pay

 

[tamz]

then the plumber how done the job will pay

There are always contras :lol:

 

[carrpaul]

Probley plumbers had not put the finishing touched / watting for materials ect no nothing site agent gives it the ok to close the plot up ( agent given the go ahead poor old plumbers gets it again )

 

[triplex]

Appreciate the replies guys. theres an article in gas installer (april?) which clearly states the G3 regs as they are at april 2010. what they go on to say is that there is a new additional requirement which says that the max water temp supplied to a bath should be no more than 48deg c. my problem is not knowing when this additional requirement was added. ie, was it in force at dec 2010?
Dont know about NHBC membership.
Problem of warm water from cold tap only exists when boiler is/has been on. Visible piping at sealed system cylinder is cu, plastic piping at rad conns. Unsure whats under the boards.
To summarise the situation if the same dissatisfaction occured in the gas industry one would consult Gas Safe. what options are available to me if they try to fob us off with excuses.

 

[snowhead]

The G3 regs are Building Regs, so Building Control would be the first point of call, but is the problem hot water at the bath too hot or cold water warm elsewhere?

What cold taps are affected by warm water, just bathroom or all cold taps?

Is the warm water at the cold tap there before any hot tap is used or only after a hot tap is used?

 

[triplex]

the hot water at the bath is excessively hot.(cyl stat set at 60c). just checked with daughter who says the only room affected is the bathroom. no hot water is drawn off prior to running cold tap.
snowhead, would you consider there to be a possible potential problem re legionella. ie stored hot water(albeit overnight) gently heated to 25c approx. Oh and thanks for your intelligent questions
.

 

[triplex]

just to clarify my last post the concern over water being too hot is that which comes from the bath tap. the other concern is that warm water has to be run off from the cold tap before cold runs out. and the latter is a problem in the bathroom only

 

[Howsie]

It's not right but you're very unlikely to get Legionella. Bath outlet is 44 deg from memory.

 

[snowhead]

Legionella isn't such a problem in domestic properties where all outlets are regularly used.
It's more a problem in commercial where large volumes of water are stored and pipework has many little or unused legs where legionella can hide out. That's not to say that it should be ignored in domestics.

It seems as earlier suggested that the boiler flow/return is adjacent to the cold supply to the bathroom, if it was me I'd be using an endoscope type camera through the ceiling below as it's less invassive initially.
It should be possible to guess where the pipe runs are given the boiler and incoming cold locations are.

 

[SimonG]

Mixing valves should be checked and adjusted annually. Has it been done since Dec 2010?

 

[triplex]

makes sense what your saying about it being less of a prob domestically yet it is frowned upon by the reg makers who do not advocate turning down your cyl. stat below 60c. thanks very much for your thoughts on the matter, will now have to wait and see what the plumbing firm suggest to rectify.

 

[triplex]

Mixing valves should be checked and adjusted annually. Has it been done since Dec 2010?

apologies Simon, only just noticed your post. No the mixing valve has not been checked since it was installed. and guess what, i've noticed a drip into the tundish coming from the press relief on the mixing valve. phew this could be a long story, but here goes. first of all let me say i am not G3 qualified. Originally there was water entering the tundish when the boiler was on, c/htg prv was replaced (by the installers), the cylinder expansion vessel press was checked and the problem still persisted. in my infinite wisdom and due to having no confidence in the plumbers i decided to download the installation instructions. Youve guessed right, it was incorrectly piped out. I then contacted heat team who had supplied the components and their man came out, verified it was incorrectly piped, he then AT RISKED the installation and got the installers back to re-pipe. Only now after reading your post have i noticed its dripping again.

 

[Reg Man]

Cold water should not be above 25 degrees C (WRAS) 20 degrees C (G3). So insulation requiredStored hot water should be 60 degrees C distribution 55 degrees C, Terminals (Taps) 50 degrees C (exception is instantaneous hot water where this may not be achieved). Mixer valves, which are normally used in public buildings or dwellings where there are aged or disabled should be set at 43 degrees C.

 

[triplex]

Am i interpreting it correctly in saying the building regs have been ignored by suppling water that is a danger by means of scalding. and that a mixing valve should have been fitted on the bath supply.

 

[triplex]

Cold water should not be above 25 degrees C (WRAS) 20 degrees C (G3).

sorry but i dont understand the above could you please explain what it means, thanking you in anticipation

 

[chris watkins]

The legal max temp for cold water (before it is classed as hot) is 25 deg C however the recommend maximum temp as laid down in BS6700 & possible building regs Part G is 20 deg C.
Does that help !

 

[carrpaul]

Are the bath taps thermostaic if so no blending valve needs fitting , do you have literature for taps some bath taps are down to 38 c , check national burns auscision web site ( you don't have blending valves in domestic property )

 

[carrpaul]

Sorry meant to say in the last part on showers

 

[triplex]

yes Chris thats very clear thanks. Paul the bath taps are not thermostatic which prompts the question
is there a device that can be fitted to the hot bath tap supply that will prevent scalding.
and was it a building regs requirement that it should have been fitted when the house was built in dec 2010

 

[jim fennessey]

On Tuesday 6th April 2010 it became compulsory in England that all new build homes or conversions or a substantial change of use premises that bath taps must not exceed 48 degrees, so must be fitted with a thermostatic mixer valve , it was to protect young children and the eldery from scolding,easily fitted , as for your cold water pipe heating up it may be just to near hot supply pipe,this can be insulated or moved,legionaires disease usually happens with stagnant water above 25 degrees it mostly happens in cooling towers it is very rare if ever happens in domestic situations, it mostly thrives at 35 degrees, i am sure but dont quote nhs baths cant be anymore than 43 degees and showers 41 degrees hope this helps

 

[triplex]

Jim. that is exactly what i wanted to hear, thank you. by you confirming my initial post it gives me a little more negotiating power in discussing with the builders/plumbers over what can be done to finally conclude this sorry and long standing matter.
many thanks to all have given input. dave the gas man, alias triplex

 

[chris watkins]

Jim. that is exactly what i wanted to hear, thank you. by you confirming my initial post it gives me a little more negotiating power in discussing with the builders/plumbers over what can be done to finally conclude this sorry and long standing matter.
many thanks to all have given input. dave the gas man, alias triplex

Triplex, I fear you may well be disappointed, if I have understood your situation correctly the bath does not have a thermostatic mixer (blending) valve installed & the property was completed in Dec 2010 (Part G changed in April 2010). As far as I am aware when the Building Reg's change a bit of leeway is always aloud by Building Control this is due to the fact that there is often little warning of what the changes are going to be & the fact that the construction of the properties may have been in progress for some length of time. It normally works on the point when planning consent was giving for the project.
I think the warming of the cold water has been fully dealt with, except possibly to check un-vented installation is correct (backflow).
Just as a side note, if a bleeding valve is installed under the bath it would still not function correctly unless the cold water issue is resolved because it would rely on the cold water being cool to temper down the hot.

 

[Reg Man]

I agree with Chris on this. The amendment came in to force on 6th April 2010 for new build properties and change of use properties. Part G 3.6 Prevention of scalding. It is very likely, that if the building project had approval for building regulations before this date, then the new amendments would not be applied, even if installed after this date.

 

[triplex]

man came out and more or less said what the last two posters say re blending valve. he goes on to say he will change the cold water valve and will alter some of the pipework, his explanation makes sense but its not going to cure the problem entirely, will probably just nibble away at it. . no doubt its going to req lagging fitting or re routing of pipes, did say that he would get back to me after discussions with his boss..