Whole building with water pressure/hot water problems at peak times

[specialhat]

Hello plumbers!

I hope someone can shed some light on this please.

I live in a Victorian building with four flats. Three out of the four have reported problems with lack of hot water at peak times, 7am to 9am ish. The fourth flat may do but we haven't heard from them in the subject.

We all have separate boilers.

I can't shower at these times because the hot water supply and water pressure is extremely patchy.

Thames Water have been fairly rubbish but eventually they came on Monday to replace three of our four stop valves outside and check the pressure.

Whatever they have done has not fixed the problem (I had no hot water whatsoever this morning), but they are coming back tomorrow to check the pressure. It does seem like the cause is internal though.


Here is what we do know:

1. Ground floor, first floor (me) and second floor are all experiencing low water pressure/no hot water, usually at peak hours between about 7am and 9am. No comment from basement.

2. The problem began in early 2015.

3. Ground floor installed a pump in early 2015, around the same time as the problems began.

4. Ground floor experience the same problems despite having a pump. (I have underlined this as everyone I have spoken to have missed this)

5. Thames Water have been to have a look at the outside stop valves. They have established that second floor and first floor have different stop valves. I do not know about the other flats but it looks likely that we have a stop valve each.

6. Three of the small stop valves were clogged up so TW have cleaned and replaced them. This has not helped the problem.


My plumber suggested:

Looks like there is an internal issue with the pipes. Suggest you run new mains pipe from stopcock in garden to your flat.
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I replied:

What about the other flats? Please note this problem affects the whole building.
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He said:

Might have to do the same with them.
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I replied:

Logically it seems unlikely that the mains pipes for all the individual flats went wrong all at the same time?
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He said:

Quite right. Wait for pressure report.
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Is there any chance that the installation of the ground floor's pump could have caused some damage in some way?

Do you have any other theories please?

 

[specialhat]

Update: TW have come back saying the pressure is ok and there is no issue on their side of the boundary.

Would could be causing peak time hot water loss in the whole property?!

 

[Ch4 plumbing]

What system do you have? Combination boiler? Unvented cylinders?

 

[Simon F]

as above, and what systems for hot water in the other flats?

 

[specialhat]

What system do you have? Combination boiler? Unvented cylinders?

I have a combi boiler. I don't know about the other flats but we all have completely separate boilers - however the problem is affecting all of us.

 

[specialhat]

None of our (separate) boilers heat the water during peak hours.

 

[specialhat]

My plumber says he'd replace the mains pipe to my flat, but can't explain why all the other flats have the same issue.
It seems very unlikely to me that the separate pipes to all the flats broke simultaneously.

 

[Ch4 plumbing]

Does water come out the hot taps but cold or does the flow of water noticeable drop during the peak times?

 

[specialhat]

Does water come out the hot taps but cold or does the flow of water noticeable drop during the peak times?

water comes out of the hot taps cold AND pressure is weak during peak times.

 

[Ch4 plumbing]

Ok so it sounds like a supply problem, did they test your working pressure and standing pressure at peak times?
Do you to the best of your knowledge have a pressure reducing valve within your property? It will be on your water main and be fairly large made of metal and plastic?
Do you know if the TW have worked on the CWM in the are All? Could be dirt in filters?

 

[Ch4 plumbing]

Point 6 of your list states that the pipes were clogged, has your plumber cleaned all filters?
Does this Leo effect your cold taps?

 

[specialhat]

I might be misunderstanding but did you see my post about Tw's latest update?
They tested pressure (off peak), said it was fine and said things are fine their side of the boundary. Basically they've washed their hands of it.

Should we get them to test it again at peak time? It was hard to get them to come out at all.

No idea re pressure reducing valves etc but will try to find out.
Thanks for your help so far.

 

[specialhat]

Point 6 of your list states that the pipes were clogged, has your plumber cleaned all filters?
Does this Leo effect your cold taps?

The outdoor stop valves were clogged and have been cleaned by Thames Water.

The cold water also has low pressure at peak times.

 

[Ch4 plumbing]

If the problem happens at peak times I would assume it's only worth testing the pressure at on peak times! I would get them back and test again at peak times!

To answer your Q, what would cause peak time hot water loss the simple answer is everyone else in the street drawing water from the water main to shower/bath and it's not big enough to supply everything!

 

[albatross]

1. Ask you neighbours either side if they have noticed. If yes(not so likely) then back to TW. If no then problem internal to your properties.
2. Ask basement flat if they have noticed. (Surely the first thing to do)
3. Logic would say that all pipes (whether there is 1,2,3 or 4) must enter the basement then rise through the building. Follow the entire route looking for half closed valves.
4. Has someone by mistake or deliberately shut some valves in the basement not realising what they do or deliberately to give themselves better pressure by giving you less?

 

[specialhat]

Thanks so much Albatross.

Basement has been empty for a while and new tenants have only just moved in. I don't think they work so probably don't try to shower at peak times but I will see. We have contacted their landlord about this five or six times, no response.

Interesting...

C4: it has suddenly started happening though. I've lived here 11 years and this has never happened before.

 

[specialhat]

Note this was all occurring while the basement was unoccupied.

 

[Ch4 plumbing]

If it just suddenly started happening then my bet would be carp in the system ( caused by works carried out on the water main) or as Albatross says possibly someone has turned something off.

 

[specialhat]

If someone has turned something off, why would it just affect us at peak times? Does it only show up when the system is under higher demand?

 

[specialhat]

(Thanks again!)

 

[specialhat]

Did you see the part about this only happening after a plumber installed a pump on the ground floor? Now, the ground floor has hot water loss too, but I wondered whether he could have damaged something when installing the pump.

It coincided with the problems starting.

 

[albatross]

Valves in the basement could have been half closed for months, regardless of whether it was occupied or not. The last tenants could have shut them.
If this was the case it would make no difference if they were using water when you did or not.
If it so so annoying knock on their door as opposed to wasting time writing letters to landlords.

 

[specialhat]

Thanks. I will see if any of the other owners/tenants will know how to look for a valve (I wouldn't have a clue!) )

 

[specialhat]

If the problem happens at peak times I would assume it's only worth testing the pressure at on peak times! I would get them back and test again at peak times!

We have contacted TW who say the pressure at their end won't change at peak times and therefore the problem must be internal.

My plumber is still insisting he wants to change the mains pipe to my flat which doesn't make sense as it's not addressing the problem which is building-wide.

We will look into the valves.

Thanks all!

 

[Tjdservices]

Was the ground floor pump a pump for a shower/bath or was it a main booster pump?