Low water pressure 8th floor flat

[eugeneboudin]

Hello all,

I have been reading the forum for quite a while, found a lot of useful information.

I have a problem with low cold water pressure in a top floor flat. It is on the 8th floor of a ex-council estate block. Both hot and cold water are supplied, so I don't have any boilers or tanks at all.

Now, I have a very thin pipe (15 mm) with cold water that above all is metre and a half long and has several bends. It was made to avoid using a broken mains stop valve, so it is connected to the stop valve of the sink and then goes to the shower.

The question is: will the pressure be better if I connect it without this long pipe? I am planning to replace the broken stop valve and connect the shower directly to the dedicated mains. Will this help?

If it will not, I know that I cannot use a shower pump or an electric shower with integrated pump because these do not allow direct connection to the mains. These pumps require a cold water tank. Can I install one in my bathroom? Any ideas how much might this cost? How big it needs to be?

By the way I have already tried a shower pump and it didn't help. So I think it is true that they generally do not work if connected directly to the mains.

Thank you very much!

 

[ianniann]

I'm just guessing, but I'd imagine that your "mains" water is actually from a tank above your flat. A typical system would have water tanks at roof level, since mains pressure would not be enough to reach up 8 floors. That would give you so-so pressure and then flats lower down probably need pressure reducers. Or there may be tanks at different levels through the building.

 

[eugeneboudin]

I'm just guessing, but I'd imagine that your "mains" water is actually from a tank above your flat. A typical system would have water tanks at roof level, since mains pressure would not be enough to reach up 8 floors. That would give you so-so pressure and then flats lower down probably need pressure reducers. Or there may be tanks at different levels through the building.

Maybe you're right and I should try with a different pump... Mine (called Triton T40) didn't make any difference. Thank you!

 

[eugeneboudin]

Does anyone know what is the difference between negative head, positive head and right pumps? Which one should I use if I am going to put in near the shower and the water tanks are far away somewhere on the roof?

 

[ianniann]

A negative head pump is designed to pump water from a level below the output. A positive head pump is designed to pump water from a level above the outlet, which is your situation (I assume).

I believe that Right is simply a brand name of pumps made by Salamander.

The Triton T40 is pretty feeble really, although I suppose that depends on your expectations.

 

[Nige F]

I'm just guessing, but I'd imagine that your "mains" water is actually from a tank above your flat. A typical system would have water tanks at roof level, since mains pressure would not be enough to reach up 8 floors. That would give you so-so pressure and then flats lower down probably need pressure reducers. Or there may be tanks at different levels through the building.

An educated guess, I would agree too- check with the council -even if they sold the whole block they usually keep the freehold / maintenance obligation

 

[dennyboy]

I do a lot of maintence on blocks of flats, the ones I work on at least upto the 9th floor have twin supplies - a rising mains that serves the CW on the kitchen sink and also all the HW in the flat (combis), the other supply comes from a tank in the lift room for the toilet, bath CW and WHB CW, above the 9th floor there is only one supply that does the H+C throughout the flat but upto the 12th floor the pressure is only .8 bar, the only way to get around it is too either fit a pump or a shower with built in pump designed to work below 1 bar becuase normal showers will not work - if I remember, the last electric shower I fitted was a mira one, think it cost £240

 

[Nige F]

Denny Boy, the pipes are calling

 

[TicklyT]

I have a very thin pipe (15 mm).... .....It was made to avoid using a broken mains stop valve.....

What size was the original plumbing that has been bypassed with this 15mm pipe?

a larger pipe will not increase the water pressure, but it may substantially increase the flow with the low water pressure available.