Hot water and heating. Totally baffled.

[Paloma12]

I've just moved into a 4 bedroom Victorian terraced house. I need to take out the bathroom and redo it - it's very old and grim. The pressure is also rubbish.
But I don't understand the water and heating at all. There is a boiler in the bedroom next to the bathroom. In the bathroom is a large hot tank
(very old). In the loft is a cold water tank. Can anyone explain how these all relate, in simple terms? And what are my options (if any) for sorting the pressure? And do I need a heating engineer or a plumber, or both? Thank you!

I expect the cold tank in the loft supplies the cold bathroom taps, and the hot water cylinder. That allows your taps to deliver water at a faster rate (litres per minute) than the incoming water main provides. If you put your thumb over the spout of a tap at tank pressure, you will be able to block the flow.

Fill a bucket at your kitchen cold sink, time it, see how many litres per minute it delivers. Without a cold tank, for example if you get a combi, that is the maximum amount that can come out of all your taps, WC ballcocks, and washing machine fillers, added together, at any one time. In an old house it may be quite low, but you can improve it by laying a new, larger plastic pipe right out to the pavement.

The service pipe might also be leads. In which case ask your water co to test the drinking water for lead content. There might be a pipe replacement subsidy.

Will you consider to change from a open vent boiler system as described above, to a system boiler (no cold water tank)? not sure how easy this can be achieved?

My house-to-be has a similar arrangement and by removing the cold tank gives me the space to convert the loft. Think the modern system boilers are very efficient these days (some experts here can suggest a few brand?)

Measuring the water flow (bucket test, above) is key to knowing what you can, or need to, do.

Our pressure was rubbish despite knowing the village had excellent water pressure. We found we still had the original lead main which was all furred up. We got this replaced (surprisingly easy & not expensive) and that allowed us to sort out all the other stuff in the house.

Do you need a plumber or heating engineer?
Some people are only one or other but many (perhaps most) do both.

You should find companies that do bathrooms AND heating and get 3 quotes. The men (or women but it is usually men) who come to give you a quote will explain how your heating/ water is working and they will suggest solutions.

I would expect them to offer a few different suggestions because there are always a few ways to acheive results and when you get very different prices you need to then understand that they are probably for different jobs.

There are some excellent plumber/ heating engineers on ukplumbersforum, and of course, my own company if you are in/near Kent!

Piglet john - it is 18 litres per minute

18 lpm is quite good, I assume the pressure is also good, but a plumber can easily test that. It is widely considered that 22lpm is the minimum needed to get the best from a pressurised cylinder, but it may be that the incoming pipe (without any restriction in the tap) may be sufficient. I would certainly ask around for local recommendations for heating engineers, and enquire if it would be suitable. Unless there is some reason not to, I would expect it to give the best results.

You say it is a Victorian terrace. Look at the incoming water pipe, both in the pavement/garden stop cock (I bet there was one when the house was built) and where the pipe rises into the house, probably the corner of where the kitchen used to be. It is probably grey lead if old, but could be iron, might be black or blue plastic if it has been replaced in the last 30 years or so. If any part of it is lead, contact your water company and ask them to do a (free) test for lead content in the drinking water. Old lead or iron pipes have outlived their reliability and are due for a change. You might qualify for a lead replacement subsidy. Also budget for replacing any old or small diameter pipes inside the house.

Can I highjack? I have been having troubles with my flow rates and water pressure in my Victorian mid-terrace that I bought a couple of years ago. I think it used to be better than now but then new neighbours moved in (who installed an irrigation system, when that's on my combi can't even start), the water company did some works next to the house on the main (and may be some grit got into the pipes), all in all it's been getting worse.

So after avidly reading the posts on this topic I went out and bought a pressure gauge and also did the flow rate bucket test as per PigletJohn's instructions.

So the flow rate is 16-18l/min, static pressure is 2.5 bar, dropping to 2 bar when another tap is turned on. And that's at 10am in the morning when nobody is really using water in other houses on the terrace and in the garden tap. I suspect pressure would be worse in the tap upstairs.

Obviously, I don't know what the pressure and flow rate are at the incoming mains - should I start fiddling with the little cover on the pavement?

So where do I go from here? I don't know what my main supply pipe is but the first bit of pipe I can see under the stairs is 15mm. Will changing main to a bigger diameter help? Or do I need to change all the pipework in the house as well, i.e. disassemble fitted kitchen, lift carpets and floorboards, etc?

And will a bigger main solve the pressure issue or just the flow rate or are they related?

My head is spinning

btw, none of the plumbers I called about poor pressure/shower even did the flow/pressure readings so losing faith a bit. Fortunately, this forum exists!

the figures you quote are quite reasonable. Test them again when pressure and flow are poor.

You neighbours are sure to be on a water meter if they have an irrigation system.

You could ask the water co if your terrace has a shared supply and if it is capable of providing adequate flow and pressure to the other houses when the neighbour's irrigation system is on.

After you get their reply, so as not to complicate things, you could also ask them if you can run a new 25mm or 32mm pipe out to the water main in the road, and what they would charge to connect it. They will encourage you to use one of their approved plumbing contractors, but in fact you can DIY and then, they will inspect the work before the trench is filled in, mostly to see if it is deep enough.

A bigger pipe will improve the flow (usually a lot) and the dynamic pressure (taps on) but not the static pressure (taps off)

If you have a meter, you can look and see if the bubble ever stops (if not you have a leak)

Thanks a lot!

I will do a diary at different times of day and call the water company.

I am not on a meter and I doubt my neighbours are. None of the houses on our terrace have a meter by default, I think you can apply to the water company to get it fitted, but it's up to you. I don't know if you must have a meter by law if you have an irrigation system, otherwise why my neighbours must have a meter? They are heavily into DIY so I think they just bought and installed without thinking.

Basically, I want to get a Megaflo or a mega combi (like Highflow 440) but I guess if I don't sort out flow/drops in pressure, I can't?

in my area you are not even allowed a lawn sprinkler without a water meter, so I'm sure the same will apply.

have a look at the website for your local water co.

Many areas in the north are much more relaxed about water meters most older houses only have them if they request them so it's not unusual to have irrigation/sprinklers without a meter.
We have one (big house, small family so works out better) with a trickle irrigation system for the kitchen garden but we calculated usage prior to installation and it's actually not a massive usage.
In our old terraced house we used to have a massive drop off of pressure at the morning shower rush due to the high demand on the street. It got worse as the street changed from mainly elderly couples to young professional families in the 10yrs we lived there.