Improving a mediocre shower - fitted the pump, now what?

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Hi everyone - first post on these forums. :)

I've been trying to improve the electric shower in our tenement flat. There is very little water pressure, so I bought and fitted a fairly beefy pump - supposedly capable of up to 5 bar. However, the flow from the shower is still disappointing - it's more like a drippy tap to be honest. The pump is making plenty of noise and appears to be working properly. It's better than before but not anywhere near what I was expecting.

The bottleneck seems to be the shower itself, especially when I turn the temperature up, it reduces the flow to a trickle.

A friend has suggested fitting a new electric shower, with more heating capacity. Our current shower is a 7kW unit, and the largest I have seen anywhere is 10kW. Is that extra 3kW really going to make a difference?

Any advice welcome!
 
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It sounds like you might be 'pumping the mains supply' which is against the rules and (as you've found out) not likely to work.
In that case, if the pump's noisy it's probably full of air drawn in from the supply.

OTOH, if you have a cold tank within the flat and you're pumping a cold supply drawn from that and the hot from a hot water cylinder also in the flat, chances are that the pump is full of air which is being drawn down the vent pipe on top of the cylinder. If so, you need an 'Essex' or 'Surrey' flange on the cylinder to prevent this from happening. The pump should then quietly pump water instead of noisily failing to pump air! Fitting such a flange is maybe not a DIY job.

Fitting an electric shower would also require a connection to a mains water supply - which might be tricky/expensive in itself and might still not give you enough pressure.
 
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Thanks for the reply.

croydoncorgi said:
It sounds like you might be 'pumping the mains supply' which is against the rules and (as you've found out) not likely to work.

Pump is fed from a cold water tank upstairs, so there's no direct connection to the mains.

The pump noises sound normal, and the flow is steady - there's none of the spluttering that I'd expect with air getting into the system. There's just not very much water coming out of the shower, and it seems to be the shower unit itself that is impeding the flow.
 
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So it's ALREADY an electric shower! You didn't say.

Well - if you suspect the shower is furred up and impeding flow - disconnect it (or the output from the pump) attach a hose or something instead and see how the pump does without the shower on the end of it.
 
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keyplayer said:
:?: He's already got one?

Just for clarification - the shower is a standard electric one, takes water from the cold tank, but has no hot connection.

Feed goes into the pump, then into the shower unit, then trickles out the showerhead... :rolleyes:
 
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You have already said that you can put more flow through it than it can heat.

Its a matter of physics, 7 kW will heat about 3 litres per minute by 35°.

Put a 10 kW shower and it will be about 40% better but still not very spectacular. Thats the problem with electric showers.

You may well need a power cable upgrade if you increase the shower power and you also need a qualified electrician.

Tony
 
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croydoncorgi said:
So it's ALREADY an electric shower! You didn't say.

Sorry! :oops:

croydoncorgi said:
Well - if you suspect the shower is furred up and impeding flow - disconnect it (or the output from the pump) attach a hose or something instead and see how the pump does without the shower on the end of it.

I might give that a try. If the shower is furred up (Glasgow is not renowned for the hardness of its water but you never know) is there any way of cleaning it out or do I just throw it away?
 
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Agile said:
Its a matter of physics, 7 kW will heat about 3 litres per minute by 35°.

I'm tempted to hold a bucket under the showerhead and see how much water is actually getting through the thing.

Agile said:
Put a 10 kW shower and it will be about 40% better but still not very spectacular. Thats the problem with electric showers.

40% improvement would certainly be welcome...


Electrical power etc. should be fine but thanks for the warning nonetheless. :) [/quote]
 
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Electric showers work on a very simple principal. There is a constant input of heat through the heater and you control the water temperature by altering the flow. Min flow= very hot, large flow= cool.

A 7 kW shower will never give you much flow at a reasonably high temp. However 10kW will will usually require upgraded wiring and pull switch.

Some showers have a double heating element and it is possible that one of the elements has failed and it is now 3.5kW

These showers should be mains fed, as toilet flushing or operating taps fed from storage tank will suddenly reduce flow and may cause very hot water at the shower unexpectedly.
 
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"Furring up" is usually noticeable when it happens in the showerhead - unscrew it from the hose to check the flow from the hose but it's almost certainly just the designed-in restriction in the shower itself which is limiting the flow.
Highest welly electric showers are 10.8kW I believe, sometimes marketed as 11kW.
SOunds like you have a bit of strange plumbing going on, a more conventional solution would probably be more satisfactory!
 
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Stuart

Which floor of the tenement are you on, which part of GLW? Almost certainly not furring in my experience, waters far too soft.

Martin
 
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martin43 said:
Which floor of the tenement are you on, which part of GLW? Almost certainly not furring in my experience, waters far too soft.

I'm in the West End of the city, near Charing Cross.

The shower is on the basement level, i.e. one floor beneath street level and one floor beneath the tank that is feeding it.


To answer the other post as well, it wouldn't surprise me if there is some dodgy plumbing going on between the tank and the pump, certainly if the rest of the flat is anything to go by.

However, the feed to the pump appears to simply be taken off the pipe that is going to the cold tap on the bath. The cold tap output, whilst it isn't exactly astonishing, seems to be pretty powerful.
 
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Stuart

Basic problem is lack of head from tank to shower, ceratinly no more than 0.5 bar which is frankly inadequate for an electric shower, even allowing for the pump. What size is the pipe from the tank? The only long term fix as others have suggested is to run the shower from the mains supply.

Martin
 
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