Could there be enough hot water pressure for a shower?

[Mick.]

Hi all, I live in a ground floor all electric 1 bedroom flat.

I do have a bathroom with a short bath in it; if possible I would like to have fitted a bath mixer tap with a shower hose fitting.

In the airing cupboard there is a cold water tank on top of an insulated tank with an off peak immersion heater .

The top cold water tank is at the ceiling level.

The hot tank below is at the top 4'2" from the floor.

Could this have enough pressure to use a bath mixer tap with a shower hose fitting?

Or is a separate electric shower unit the only way?

Hoping someone can advise me.

Mick.

[Tim Downie]

I think you'll be struggling with a gravity fed shower with such a low head. You could probably add a pump although I'm not sure about adding one if you've got a combined HW tank & header tank.

Tim

[muymalestado]

Totally agree with Tim; from experience of header tank on floor above giving a head of about 4'6", if that. This was not enough, until we put in an Aqualisa. That gave lots of water at a low pressure. Adequate but not ideal.

Complete re-plumb job eliminated header tank to make a pressurised system. That is the way to go, if possible.

My query concerns a relation's flat in your situation. Could a single electric pump power the cold AND the hot water from the header tank ?

[The Natural Philosopher]

No.

No. convert the existing tank to a mains pressure one, and live happily (amd quietly)ever after.

[The Natural Philosopher]

if the pump is of sufficient capacity, it will empty the header tank faster than it refills. And the hot water cylinder too. heap of crap are those tanks. even a combi is a better option.

But a mains pressure tank is marginally cheaper than a combi of decentish power levels.

[Heliotrope Smith]

You would be lucky to get more than a dribble of water through the shower as the head would be only a foot or so below the cold storage tank.

Get a short length of hose and attach it to the tap or hold it with your hand around tap and hose, turn on tap and start to raise the end of the hose. As you raise it the water flow will slow and almost stop the closer to the ceiling you get.

[Tim S]

Mick. coughed up some electrons that declared:

Been there- house I was a kid in...

This fact is not a factor in a standard open vented system - only the cold tank height matters.

Yes it does work - but fairly poorly.

We had an Aqualisa shower mixer in exactly that setup. It was OK for hair washing sitting in the bath and you just about have a shower standing up but it was poor.

Have you considered a shower pump - that's a standard solution to this problem - pressurised the hot and cold feeds (the pumps are actually double pumps with a common motor).

Cheers

Tim

[NT]

set the pump to the minimum usable speed to address the tank refilling issue. If necessary use a dropper to do this

[NT]

Would 1 or 2 central heating pumps be sufficient for this? They do seem to have good life expectancy.

NT

[chudford]

Is your water heater a Pulsacoil type like this:

it is then it supplies water at mains pressure and already has a pump so will give you plenty of pressure for a shower.

[Heliotrope Smith]

this

> NT

Would 1 or 2 central heating pumps be sufficient for this? They do seem to have good life expectancy.

Central heating pumps will not be any good at all to pump water up to a shower. They are only circulators and will not pump to any significant pressure.

[YAPH]

They would but they'd corrode badly in fresh water. Grundfos do one designed for hot-water boosting, which contains a flowswitch too, to switch the pump on when water starts flowing (under gravity - so there's got to be enough un-boosted flow to kick it in). Or an ordinary double-ended shower pump can be used single ended. Either way the OP would need to ensure that the little header tank of the cylinder doesn't empty when the pump is running. Replacing the standard filling valve with an equilibrium valve (e.g. "Torbeck") may help, as would adding a second filling valve to further increase the flow.

[Mick.]

Hi thanks for answering, It is round not square but does look Similar All I can see written on it is: Harton Heating Appliances Ltd, Hatley Road, Thamesmead, Erith Kent. I cannot see a model no anywhere on it. The block of 4 flats were built in 1986, and as far as I have been told this is original equipment.. I will try a hose on the hot tap to see the pressure at head height but there does seem some pressure. Mick.

Is your water heater a Pulsacoil type like this:

it is then it supplies water at mains pressure and already has a pump so will give you plenty of pressure for a shower.

[NT]

In this case though the water already reaches the shower head, just with not much flow.

NT

[Heliotrope Smith]

In this case though the water already reaches the shower head, just with not much flow.

Correct, but ch pumps will still not increase the flow very much.

I have even seen two ch pumps connected in series with very little effect on the flow rate.

Also there is the issue of rusting out in no time as raised by a previous contributor.

[Heliotrope Smith]

I have had a look at the Harton web site.http://www.hartons.co.uk/boostedhotcoldunits.htmlIt looks like you have a system 4 or 5 in which case it looks as though you would not have a problem using the type of shower you have in mind.

[NT]

cheers

NT

[Mick.]

Hi all, Thanks for the help. It does seem to be a system 4 or 5 but the ones on the website seem to have a pump fitted on the front of them, and the one in my flat does not! Perhaps this was to save money as around 90 flats were built at the time. I did get a "push on" cheapish shower, it does work at lower levels but on trying to use it standing up the hot feed reduces to a trickle.