Shower pump fitting for open vented tank

[Mark2000]

Hi all, first post here, any advice greatly appreciated.

I live in a flat on a high floor, cold water comes from communal tank 10+ meters above me and is very powerful. However the hot water comes from an open vented economy seven heated water cylinder and the head to the taps is about 1 metre and is extremely weak, flowing at around 2 litres per minute. The tank is massive, about 2+ meters tall and probably contains about 200 - 300 litres.

I would like to fit a shower pump to get a much stronger flow at the hot taps in bathroom and kitchen. The plan is to get a positive head single impeller shower pump which I will fit myself close to the cylinder (I am very handy at this sort of stuff). This one seemed good value and good quality -

http://www.salamanderpumps.co.uk/pumps/ct-range/ct-55-xtra/

I was going to get this one below but looks like the flow wont be strong enough to trigger it (needs 3-4 litres per minute) and I doubt it is any good for that price -

https://www.amazon.co.uk/gp/product..._rd_t=36701&pf_rd_p=867551787&pf_rd_i=desktop

Will the more expensive Salamander be OK for my system? Will the 2 litres per minute be enough to trigger the pump? Is 1.5 bar a good figure for the output? Will the noise be OK for a block of flats? Noise really carries in this block. A quiet pump is high on the list. Any other models I should consider?

One thing I noticed is all these pumps seem to show schematics with connection to a sealed or possibly vented hot water cylinder (not an open vented one like mine) - so will these pumps work OK with my type of system?

Any advice would be greatly welcomed. Thanks in advance!

 

[Mark2000]

By the way the basin taps in bathroom and kitchen are mixers

 

[Steelmasons]

Does a "vented" cylinder differ to that of an "open vented" cylinder????

 

[flameport]

If the hot water cylinder is a combination (Fortic) type with a cold cistern above the heated water all contained within a single unit, a pump cannot be used - the cold cistern will only hold a small amount of water which will be depleted very quickly if the output is pumped.
However that type are not usually '2+ meters tall and probably contains about 200 - 300 litres.'

What make / model of hot water cylinder is it? Picture of it and the pipework would be useful if no make or model can be found on it.

 

[Mark2000]

As far as I know an open vented system is one which has (as mine does) a totally open top ie at the top of the cylinder there is a lid (completely loose that just perches on top) and when you take this off there is a hole about a metre across and you can readily see inside the cylinder. A vented system has a cylinder that is basically sealed but has a vent pipe that goes to the cylinder in the loft to relieve excess pressure. That was my understanding anyway.

My HW cylinder does not contain a cold water cylinder. The cold water is supplied from a communal storage tank in the roof space of the block and is about 10 metres above my flat and has I estimate about 1 bar head.

The HW cylinder in my flat contains 2 elements that heat the water and it is heated at night on economy seven. It then gravity feeds all taps at extremely low pressure. It looks somewhat like this (not mine just a photo from google).

Thanks for the replies everyone and any further advice greatly appreciated.

I am wondering in fact if I might need a negative head pump.

 

[Nige F]

Like flameport says - and your generic google pic shows, you have a fortic cylinder. What we need to know is the capacity of the top tank. Can you put a Flexible tape measure in it and post the depth and width of it in mm. or cm.

 

[dilalio]

Post some photos of your actual install, although it doesn't sound like you'll be able to do what you want with what you have!

 

[Mark2000]

Thanks for the replies guys.

I definitely don't have a Fortic cylinder. The cold water in my flat comes from a communal tank on the roof and is gravity fed into the HW cylinder and is controlled by a ball valve in the HW cylinder. The HW cylinder does not have a separate tank for cold in it. It has hot water only in it.

(I am sorry if the picture I included was misleading. My tank which I cannot unfortunately photograph looks very similar to the one I included but is not a Fortic.)

The HW cylinder then heats that water overnight and it supplies the taps by gravity with about 1 metre head thus slow flow.

Having looked at lots of info on the net I am strongly inclined to buy this device-

http://www.showerpowerbooster.co.uk/product/fully-automatic-shower-power-booster-sp2/

It seems rather expensive (and small!) but I understand it is very quiet and I hope I can attach it to a lighting circuit thus simplifying electrical work. The manufacturer tells me it will work with my setup. It has a modest boost of 0.5 bar but I think that will be enough to solve my problem.

What do you think of my plan?

Thanks.

 

[Steve]

When you look into the top of the cylinder can you see all the way down?

If as you say it is a hot water tank, open at the top, you'd have horrific condensation.

 

[Mark2000]

Ok, admission time - I think it IS a Fortic! I thought that a Fortic was a tank that supplied both hot and cold water to the flat ie the cold water in my tap came from a small tank in the Fortic but I now understand that the cold water in the Fortic tank is to supply the hot water heating section (of the Fortic) only.

I am still sure that the cold water comes from the communal roof tank.

Anyway I guess it makes no difference hopefully as the tank is still a vented gravity fed so I should be able to use the small pump as shown above. If the water flow goes from 2L per min to 8L per min as claimed I will be happy.

By the way there is condensation on the lid when I remove it but it doesn't seem to escape outside much.

Any more advice anyone? Thanks.

 

[stem]

When you questioned the manufacturer as to their products suitability, did you tell them you had a Fortic? If not I would suggest that you check with them again.

With traditional centrifugal impeller type shower pumps, they cannot be used with a Fortic cylinder because the small cold water feed tank won't fill fast enough and you would run out of water. However the device you are considering seems to be less powerful, so you may be OK, but only the manufacture would be able to confirm for certain.

 

[dilalio]

The guy who invented the showerpowerbooster has been on this forum so search for it on here and maybe you can pm him!