Advice on fitting a power shower

[griffta]

Hi all,

My brother has moved in to a new house which has a gravity fed central heating and hot water system. There is a hot water cylinder in first floor airing cupboard and hot water and central heating header tanks in the loft.

His current shower is a standard mixer valve (non-thermostatic from what I can tell). It's fed with hot water via 15mm pipe taken from a tap off the 22mm hot water feed from the top of the hot water cylinder. The cold is fed from a 15mm tap off the cold water feed to the hot water system (gravity side, not mains).

I understand that I can upgrade this installation to a power shower by installing a dual impeller positive head pump. I plan to fit this in the loft by cutting the hot and cold supply pipes to the shower and plumbing in the pump.

I had read that the hot water supply for a power shower pump should come from dedicated tap lower down the hot water cylinder. The explanation for this is to prevent air bubbles at the top of the tank getting in to the pump, reducing it's life. Is this strictly required? If so, what would be required to add a second tap off point to the tank?

Any other general advice would be greatly appreciated.

Matt.

 

[dilalio]

You don't need to tap into the side of the cylinder. You can use a Surrey flange in the top of the cylinder to facilitate pumped draw off for the shower as well as maintaining the normal, gravity fed supply to other outlets. Furthermore, you can 'sometimes' get away with the need for a Surrey if you put in a downward pointing T off the 22mm hot feed from the top of the cylinder BEFORE the vent pipe up to the F&E tank.

 

[Steelmasons]

F & E "tank" Dialilo"?
So cut a tee into heating open safety vent??
Maybe confused with the CWSC?

 

[Madrab]

Try and avoid putting the pump in the loft if you can. A setup like that can get very temperamental when the pump and outlet(s) get older and when it's up above the HW cylinder, near the cold cistern and any fluctuation in available head/flow can affect reliability.

Ideally you want a dedicated feed using a flange as Dilalio mentions. You can cut a downwards facing Tee into the HW supply pipe, prior to the HW vent Tee but you then really need a rising HW supply pipe to ensure air isn't drawn down so easier with a flange.

If you are putting it up there you will also need an anti gravity loop from the HW cylinder feeding up to the pump.

If you are unsure Matt, then I'd recommend getting someone in. Adding a dedicated pump , especially in the loft needs to be setup correctly. They can't usually just be slotted in. Better still though, buy an all in one power shower unit with an inbuilt pump, much easier to DIY fit correctly.

 

[dilalio]

F & E "tank" Dialilo"?
So cut a tee into heating open safety vent??
Maybe confused with the CWSC?

Just checking Steel... just checking

 

[dilalio]

Try and avoid putting the pump in the loft if you can. A setup like that can get very temperamental when the pump and outlet(s) get older and when it's up above the HW cylinder, near the cold cistern and any fluctuation in available head/flow can affect reliability.

Ideally you want a dedicated feed using a flange as Dilalio mentions. You can cut a downwards facing Tee into the HW supply pipe, prior to the HW vent Tee but you then really need a rising HW supply pipe to ensure air isn't drawn down so easier with a flange.

If you are putting it up there you will also need an anti gravity loop from the HW cylinder feeding up to the pump.

If you are unsure Matt, then I'd recommend getting someone in. Adding a dedicated pump , especially in the loft needs to be setup correctly. They can't usually just be slotted in. Better still though, buy an all in one power shower unit with an inbuilt pump, much easier to DIY fit correctly.

Bugger! And yes... Try and put the pump next to the cylinder - not in the loft else you'll be reducing the positive head at the pump which can cause it to stall!
I really should pay more attention on a Sunday afternoon!

 

[Steelmasons]

- not in the loft else you'll be reducing the positive head at the pump which can cause it to stall!

I usually find the cold supply is fine although the hot supply tends to air lock due to air trapped between cylinder and pump if not used frequently.
Reducing the positive head dilalilo?

 

[dilalio]

AquaLisa Quartz digital

 

[JimCrow]

Hi all,



His current shower is a standard mixer valve (non-thermostatic from what I can tell). It's fed with hot water via 15mm pipe taken from a tap off the 22mm hot water feed from the top of the hot water cylinder. The cold is fed from a 15mm tap off the cold water feed to the hot water system (gravity side, not mains).



Matt.

The shower valve should have it's own dedicated cold feed from the CWSC.

 

[dilalio]

Hi all,



His current shower is a standard mixer valve (non-thermostatic from what I can tell). It's fed with hot water via 15mm pipe taken from a tap off the 22mm hot water feed from the top of the hot water cylinder. The cold is fed from a 15mm tap off the cold water feed to the hot water system (gravity side, not mains).



Matt.

The shower valve should have it's own dedicated cold feed from the CWSC.

Correct