Mains Water Pressure Problem?
Discussion
This is probably a very simple question, but I couldn't find anything on search so here goes,
We have just moved into the building site that is our new home, don't ask schools and local council, and are having a problem with the mains water pressure. The pressure is fine to run one tap but if another is turned on both drop to virtually nothing. If you wash your hands after using the toilet then the cistern does not fill up until you turn off the tap. The boiler is a one year old combi and seems to run the water and heating fine, 12.5l /min hot water flow-rate, and when you are showering it does not run cold it just dries up! Now we are intending to put another shower into a new en-suite and I was wondering if there is anything I can do to stop the loss of pressure. There is no tank in the loft at all and I was advised that using a shower pump with a combi boiler was not a good idea. Could I install a cold water tank in the loft and then run a pump from that to the water supply thus creating my own mains pressure?
Any ideas welcome as I would like to sort out the problem whilst I am building and not have to try and live with it and then decide in a few months time that I really need to deal and have to start al over again.
Many thanks,
Jon
We have just moved into the building site that is our new home, don't ask schools and local council, and are having a problem with the mains water pressure. The pressure is fine to run one tap but if another is turned on both drop to virtually nothing. If you wash your hands after using the toilet then the cistern does not fill up until you turn off the tap. The boiler is a one year old combi and seems to run the water and heating fine, 12.5l /min hot water flow-rate, and when you are showering it does not run cold it just dries up! Now we are intending to put another shower into a new en-suite and I was wondering if there is anything I can do to stop the loss of pressure. There is no tank in the loft at all and I was advised that using a shower pump with a combi boiler was not a good idea. Could I install a cold water tank in the loft and then run a pump from that to the water supply thus creating my own mains pressure?
Any ideas welcome as I would like to sort out the problem whilst I am building and not have to try and live with it and then decide in a few months time that I really need to deal and have to start al over again.
Many thanks,
Jon
fatboy b said:
Why shouldn't we ask the schools or local council?
We had places in the local schools we liked for both children to start last summer, but I was warned off for a Tour and so my wife did not want to move the kids away from their established support network during such a potentially traumatic time. The schools, and the council, agreed and we set the start date for them as the bigging of the Summer Term, after the Easter break. Unfortunately the council decided to change their entrance criteria just before Xmas and took back the places without informing us, and the school rang us up to ask why we no longer wanted the places, especially as SWMBO had rung the week before to ask about uniform! I appealed to the council to give us back our places, and with a bit of top cover provided by my Chain of Command, managed to get them back but we had to start immediately or the council would take them back again. Given that we had planned the extension around my Tour and the known school dates moving the family into a building site was fairly traumatic, not only for us but also for the builders who had to reinstate some of the services, mainly in the kitchen and bathroom, that had been removed as these rooms are changing. So the wife and kids are living in part of the old house with makeshift facilities, which makes for great conversations inthe evenings, not!mk1fan said:
Water tank in the loft will solve your pressure problems but that is a lot of work.
Sounds like the local water board needs prodding, regularily.
Whilst I have the joists exposed in the extension and access though the window holes I can get reasonably large stuff into the attic relatively easily. I will also have to attach new pipes to all of the systems for the new kitchen and bathrooms so will have to drain down and bleed everything so I am not sure how much additional work adding a tank would be. Can I add it to the supply side and thus increase the pressure of the cold water as well? What size of pump should I be looking at, it will be a reasonably sized 1950's 4 bed when I am finished with a family bathroom and an en-suite. Is it going to be very expensive, another few hundred could be managed, a few thousands probably not. So many questions I know,Sounds like the local water board needs prodding, regularily.
Thanks again,
Jon
At a guess I'd say....
Either the main stopcock is not fully open or the supply pipe is semi blocked/crushed. That you get good pressure at low flow rates show the pressure in your area is fine.
Edited to say :- do both taps really drop to nothing or just half? Hhmmm
Either the main stopcock is not fully open or the supply pipe is semi blocked/crushed. That you get good pressure at low flow rates show the pressure in your area is fine.
Edited to say :- do both taps really drop to nothing or just half? Hhmmm
Edited by ThatPhilBrettGuy on Wednesday 9th February 17:11
Make sure you don't confuse pressure with flow. It sounds more like you have a flow-rate problem, as previously mentioned this could well be the stopcock not open enough or a blockage. Has it always been that bad? If so, whoever put that combination boiler in needs a kick up the arse. Combination boilers (and I speak from nearly 30 years experience) are no good in big houses. A couple of outlets, perhaps, but no more and certainly a bath is a problem for them. If the board come out and test they will be happy, in many areas, with 1Bar. They may well find quite a bit more than that, but supply pipe restrictions may well leave you with a poor flow. This is when you need a storage tank in the roof and a proper hot water supply from a cylinder. See if they will test flow at THEIR stopcock. I'm not sure what they'll guarantee you there, but if it's good there then you might look at running a new MDPE main in.
That sounds about right Ferg, the flow remains constant and is thus split across the open taps. I'll find the stopcock and see if it turned on fully, I know that the builders have turned it off at least once as they have been playing with the supply. As for the combi, we did not fit it, the previous owners did and so recently that I was not planning to change it. I will be running wet underfloor heating downstairs (approximately 90m2) and a family bathroom, with a thermostatic mixer over a bath, and an en-suite with a fully installed shower, SWIMBO has seen these large "rain style" shower heads with a diverter that she likes. The shower she has seen is rated at 7l/min and the combi is rated at 12.5l/min so it should be up to running both showers concurrently. If I need to fit a new boiler then that is a large expence that I was not planning on!
Well the main stopcock was not fully open and so I opened it and the situation is a little better but still not really great. I will ask the water company to test the flow and pressure but I suspect that it will be ok for them but probably not for what I want to do. Do I need to replace the entire system and if so what would be best? Can I reuse the combi boiler or is it not right at all?
Jonleeper said:
Well the main stopcock was not fully open and so I opened it and the situation is a little better but still not really great. I will ask the water company to test the flow and pressure but I suspect that it will be ok for them but probably not for what I want to do. Do I need to replace the entire system and if so what would be best? Can I reuse the combi boiler or is it not right at all?
If you DO go down the route of putting an indirect cylinder in and stored water you CAN use the combination boiler. Best to use the instantaneous hot for maybe one tap, or even a shower, then have all the other hot demand from a cylinder.So what would be your recommendation, if the water board do come back and say that the pressure and flow rate are ok. I can feed the en-suite, shower and sink, directly from the combi boiler and then feed the rest of the house from a tank? Would I need to install a cold water tank to maintain the pressure and flow on the cold side? Will I need a shower pump to feed the family bathroom?
I am getting slightly confused about the best way forward. The total hot water requirement for the house is;
Upstairs;
En-suite: Shower (thermostatic mixer with "rainwater" head and diverter), sink and toilet.
Family Bathroom: Bath with thermostatic mixer shower over and sink.
Toilet: Toilet and sink.
Downstairs;
Kitchen: Sink.
Shower-room: Electric shower (I thought that the combi would struggle with another thermostatic mixer and it will only be used very occasionally when the house is full!), sink.
The heating will be wet under-floor throughout the downstairs and radiators upstairs with heated towel rails in the bathroom and en-suite. I was going to look at the cost of radiators and see if I could replace the existing radiators with oversize items so that I can reduce the temperature of the heating side of the boiler for better efficiency.
Hopefully this makes some sense and I am not a million miles away from the right idea.
Many thanks for all your assistance,
Jon
I am getting slightly confused about the best way forward. The total hot water requirement for the house is;
Upstairs;
En-suite: Shower (thermostatic mixer with "rainwater" head and diverter), sink and toilet.
Family Bathroom: Bath with thermostatic mixer shower over and sink.
Toilet: Toilet and sink.
Downstairs;
Kitchen: Sink.
Shower-room: Electric shower (I thought that the combi would struggle with another thermostatic mixer and it will only be used very occasionally when the house is full!), sink.
The heating will be wet under-floor throughout the downstairs and radiators upstairs with heated towel rails in the bathroom and en-suite. I was going to look at the cost of radiators and see if I could replace the existing radiators with oversize items so that I can reduce the temperature of the heating side of the boiler for better efficiency.
Hopefully this makes some sense and I am not a million miles away from the right idea.
Many thanks for all your assistance,
Jon
Well I was in the local City Plumbing store chatting about stuff with the clerk and a local plumber came in and joined in the conversation. He was of the opinion that an un-vented cylinder system was the best choice but that the pressure and flow should be ok in the area. He did state that there is a real issue with lime-scale and that he had found problems with steel pipes corroding and blocking. Now given that this house was built in the 1950's he thought that it was quite likely I have a steel pipe joining the mains to the house and that is probably hadn't been changed since it was installed. The mains have all been upgraded to plastic, he thought, but it is quite likely I have a restricted flow into the house from the corrosion in the steel pipe. The water-board have been contacted and are due to come round on Mon AM to test the pressure and flow into the house. This will give me a figure for the flow and pressure, but what should I be expecting or what is acceptable? I know that they will advise but I would like a little knowledge so that I can be, at least, a little informed when I speak to them.
Many thanks,
Jon
Many thanks,
Jon
If the flow rate problems can't be resolved, what about using an accumulator?
http://www.tradeplumbing.co.uk/Cold-Water-Accumula...
http://www.tradeplumbing.co.uk/Cold-Water-Accumula...
Deva Link said:
If the flow rate problems can't be resolved, what about using an accumulator?
http://www.tradeplumbing.co.uk/Cold-Water-Accumula...
What an odd link!http://www.tradeplumbing.co.uk/Cold-Water-Accumula...
You're spot on, Deva, in suggesting an accumulator for the flow-rate, but that link seems to be advocating a storage tank, a pump and an accumulator to overcome PRESSURE problems. All very well, but you'd have to be keen and desperate with your water supply to go to all that trouble...
Ferg said:
What an odd link!
I just picked the first Google hit for water accumulator. I thought if I just said "accumulator", the OP would have no idea what I was talking about.Now I've read it, their wording sounds more like they're describing a standard cold water cistern with a pump on the output.
Edited by Deva Link on Saturday 12th February 11:49
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