Removal of cold water tank for bathroom taps?

[BigTomorrow]

I live in an apartment and have a cold water tank in it. The cold water tank feeds the cold water tap in the sink and the bath. Recently, I refurbished my bathroom and, according to the plumber that fitted the new taps, high-pressure taps were fitted. Consequently, the water that comes out of taps is of a low volume and a low rate. I wonder if they could be supplied by the main water supply? Please let me know if this is possible. The plumber that fitted them said there was a reason it could not be done, but I can’t remember what he said. There appears to be no good reason for the cold water tank. If it helps, the apartment was built in and around 1986.
If you have any questions, ask away. Hopefully, I can answer them.

 

[Deleted member 120897]

We need to know what type of boiler you have before answering this question. If you have a water tank I’m guessing you have a hot water cylinder too?

 

[BigTomorrow]

Thanks for your reply. Yes, I do have a hot water tank. The apartment has Economy 7 for heating the water, or, in other words, an immersion heater.

As an aside, how can I make sure that the water from the cold water tank is safe to use? The apartment has not been used for quite a while.

 

[Deleted member 120897]

Depends on how long is a long time, 30 days and it’s supposed to be cleaned out afaik. As for the tanks, this is why you can't have mains fed because your hot water isn’t mains fed. taps should be suitable or a pump installed.

 

[BigTomorrow]

Depends on how long ia a long time, 30 days and it’s supposed to be cleaned out afaik. As for the tanks, this is why you can't have mains fed because your hot water isn’t mains fed. taps should be suitable or a pump installed.

Hi Chris,

For over a year, the water in the tank has been in there. I just bought the apartment. I suspect that allowing it to run dry would not be sufficient. Can you recommend a way of getting it cleaned and making sure the water is safe? And, how much should it cost? These questions are open to anyone else who reads this.

Regarding the hot water cylinder, how big a job is it? And, how much should it cost?

 

[Deleted member 120897]

No, it’ll likely have to be disinfected. Not something I’ve done before, only heard about it. Contact your local water undertaker or these if no none on here can assist you. No ideas on cost, I’m not self employed or don’t know if anyone getting it done.

What are you asking about regards the cylinder?

 

[Ric2013]

Realistically though, how sterile is a new cistern or cylinder when we first put one in anyway, and how will that truly differ from the situation we have here?

Surely siphoning out the cistern with a hose, giving the cistern a good wipe, then refilling the cistern; followed by bringing the cylinder up to 60° temperature, waiting an hour, running the hot taps until there is no more hot water and heating the cylinder up again should result in a system that is no more contaminated than any other typical system that is currently in use? I suppose you could run some Milton tablets through the system if you were that bothered - a typical cylinder contains 117l so it would certainly be affordable.

I know you won't have made up the 30 day statistic, but what's that based on out of interest? If you were away from home for 30 days, would you really expect to do any more than I have suggested above? I can't honestly say I would personally go to more than that level of effort unless I had family who were immunocompromised.

 

[Chuck]

Realistically though, how sterile is a new cistern or cylinder when we first put one in anyway, and how will that truly differ from the situation we have here?

BS8558, says that hot and cold water services should be cleaned, flushed and disinfected in the following situations:

• On completion of a new water installation or refurbishment of a hot and cold water system;
• On installation of new components, especially those that have been pressure tested using water by the manufacturer (see the manufacturer’s instructions);
• Where hot and cold water is not used for a prolonged period and has not been flushed as recommended or the control measures have not been effective for a prolonged period. For example, this could be as little as two or three weeks, but will depend on the ambient temperature, condition of the water system, potential to exposure to aerosols and the susceptibility of the users considered in a specific risk assessment;
• On routine inspection of the water storage tanks, where there is evidence of contamination or stagnation;
• If the system or part of it has been substantially altered or entered for maintenance purposes that may introduce contamination;
• Following water sampling results that indicate evidence of microbial contamination of the water system;
• During or following an outbreak or suspected outbreak or of legionellosis linked to the system;
• Or indicated by the legionella risk assessment.

Surely siphoning out the cistern with a hose, ...

A proper job includes checking the concentration of disinfectant during and after the process.

I find it quite difficult to assess the risk associated with these systems. Thanks to a 'dead rat/squirrel in the tank' experience, I really don't like any cold tap that is likely to be used for teeth-cleaning, etc. being on an indirect feed, and I avoid showers that have an indirect feed. On the other hand, slips and falls in UK bathrooms probably injure/kill more people than contaminated water.

 

[Ric2013]

BS8558, says that hot and cold water services should be cleaned, flushed and disinfected in the following situations:

I've seen this done on the private supply at the Centre for Alternative Technology when the department responsible finds the system is contaminated, but then they don't make routine use of chlorine AFAIAA and rely on sand filters and UV lights instead.

A proper job includes checking the concentration of disinfectant during and after the process.

I find it quite difficult to assess the risk associated with these systems. Thanks to a 'dead rat/squirrel in the tank' experience, I really don't like any cold tap that is likely to be used for teeth-cleaning, etc. being on an indirect feed, and I avoid showers that have an indirect feed. On the other hand, slips and falls in UK bathrooms probably injure/kill more people than contaminated water.

My house (and the one I grew up in) has mains cold to ALL cold taps, so I suppose it is fair to say the situations are not quite analogous and I suppose that has altered my perception. The dead rat / pig situation shouldn't happen, but the only compliant cisterns that are properly fitted as per the Water Regs that I have seen are those I have personally installed, so I do see why you don't trust stored water.

Are you telling me you always disinfect whenever you alter potable pipework or just in specific cases? I mean, would you do it for a new bathroom where you've modified the pipework? I hadn't seen this in the Water Regs, no one I have ever worked for did it, and all I've ever done is flush through with fresh water for long enough to change the pipe contents 10x (or a heat, drain, and refill in the case of a cylinder).

Is BS8558 now compulsary, or just the gold standard a commercial client may ask you to work to? It sounds a bit unlikely to be done in domestic situations, or am I out of date with what other people are actually doing?

 

[Chuck]

...
Are you telling me you always disinfect whenever you alter potable pipework or just in specific cases?
...
Is BS8558 now compulsary, or just the gold standard a commercial client may ask you to work to?

My point was really only that if you do need to disinfect a system you should make sure you use the right concentration for the right time and flush it out properly afterwards.

I don't have a copy of BS8558 to hand and I haven't read the latest edition but IIRC it says that flushing is always necessary but not disinfection. Disinfection is for higher risk cases, e.g. when buried pipes have been opened, in multiple occupancy buildings, extensive works, etc. My reading would be that if you are working clean and using new or disinfected fittings then flushing is all that's needed for a bathroom upgrade in single occupancy domestic premises.

You're correct, of course, British Standards are not laws or regulations. Following them is an 'easy' way to be sure you are complying with the relevant laws/regulations but they aren't necessarily the only way and may be overkill. They are indeed very useful as shorthand for for simplifying contracts while making sure everybody understands how the job is to be done. I do wish they weren't so prohibitively expensive for individuals as they are a really good source of information and good practice.

P.S. I think that @ChrisB1982's '30 day' figure is in BS8558 somewhere.

 

[Deleted member 120897]

P.S. I think that @ChrisB1982's '30 day' figure is in BS8558 somewhere.

Thanks, I haven’t read that BS, the figure was from when I did my water regulations certification, and possibly from my water undertaker’s regs department back when I was on plumbing, so although BS isn’t a requirement, water regulations is.

 

[Ric2013]

I do wish they weren't so prohibitively expensive for individuals as they are a really good source of information and good practice.

I think some public libraries can get you a login to see them, but I may be remembering my university days and the Athens login I was able to get from it, which is, sadly, no longer valid.