Shower Pump All aspects of plumbing questions and answers, help, tips and information

[kipper]

Hi all,

I want to replace the electric showers in by bathroom and ensuite with Thermostatic mixers.

I have a combination cylinder in the airing cupboard but strangly enough also have a cold tank in the loft. Consequently the cold water pressure is fine but the hot is pretty poor.

My plan is to fit a single impeller pump to the hot supply (about 2.5 bar) and use this to boost the power to all hot taps. Is there any reason why this should not work and do you have any advice on doing this?

Thanks

Kipper

[marrtin]

Sorry but I don't know what you mean by a combination cylinder?

You cannot use a single impeller pump providing a shower. The hot and cold feeds must always be at equal pressure and fed from the same type of supply. ie, High pressure direct from the mains or low pressure from the header tank, with or without a double impeller pump.

[rosebery]

I don't know what marrtin has already written as his post hasn't appeared yet but I would say that's not going to work. You need to have both hot and cold feeds balanced ie at the same pressure. The answer is to pump both.

Cheers

[kipper]

Thanks,

To clarify the combination cylinder has the cold tank directly on top of the hot tank this feeds the hot tank below but gives poor hot pressure. The purpose of the pump was to improve the hot water pressure to all taps (not just the showers). At the moment the pressure is very uneven with the cold pressure being fine and the hot beeing rather poor

[simpleton]

i think kipper means a "HarcoPak" type bulk storage heater. fitting a pump is expensive, and is just another thing to go wrong. I think your best sticking with the electric showers, if youve got the type of system that i think youve got (they were popular in the 70s) then your always going to have poor delivery on the hot water side of things

[rosebery]

Ah yes - the type to be found, perhaps, in a flat where there is no roof space to accomodate a more conventional CW Storage tank.

I'm tempted to ask if your cold taps are fed direct from the mains because I can't see any other way that there would be the sort of pressure differential that you report.

Your answer will dictate the next stage.

Cheers

[marrtin]

Combination, ah yes of course I know what they are, but it will give you a problem even with a normal mixer shower. The problem is it emptying too fast. If fitting a pumped (power) shower it is recommended to double the size of the stored cold water which equates to over eight times the volume stored by a combination tank.

[kipper]

Your correct in that I am told these combination cylinders are normally found in flats etc, but I have a 4 bed house with a large loft.Strangely enough the coldwater actually comes from a seperate tank in the loft as well.

I am just trying to figure out the most cost effective way to get enough hot water pressure for both bathrooms

[bummer2220]

hi i am new to the site but have found it usefull, i to have the same type of system and have been continplating fitting a power shower. after studying it the system only calls for a 75 mm (3" ) from bottom of the cold water storage to the top of the shower ( wall mounted type ) , it does need an equal water pressure for hot and cold and this is were the problem starts as this type of water tank only has one cold out let that goes from the bottom of the cold cylinder to the bottom of the hot cylinder , roseberry is correct about the taps being fed direct from the mains and this would nacker up any pump fitted to any part of the sytem , so you would need to break into the copper pipe that runs between the hot cylinder and cold and use this to feed the pump that would then feed your taps . sorry if i have gone on a bit and coorct me if i am wrong

[marrtin]

Kipper, your best bet is to probably change the combination cylinder for a standard one and feed it from the header tank in the loft.

This would give you a larger store of hot water as well as increase the pressure. You could then fit a pump to turn a mixer shower into a power shower.