Shower installation but low pressure mains water

[auldyin]

Advice required please in respect of installing a shower in a family bathroom within an old stone and slated house.

The AGA boiler provides hot water to the (radiator) central heating system only. Domestic hot water to the kitchen, family and en-suite bathrooms is provided by means of an immersion heater in the hot water cylinder.

The cold water mains feed to the family bathroom has low pressure.

Consequently should I be thinking of installing an electric shower with pump such as the Mira Elite ST 9.8kW or would it make better sense to install one of the Grohtherm range and if so which model.

 

[JohnD]

Is there a cold water tank in the loft, supplying the cylinder?

What's the flow and pressure like from the hot taps?

 

[auldyin]

Is there a cold water tank in the loft, supplying the cylinder?

What's the flow and pressure like from the hot taps?

Yes - theere is a cold water tank in the loft supplying the cylinder.

The flow and pressure from the hot water feeds in the family bathroom are greater than the cold water feeds.

 

[JohnD]

then you could supply the shower with hot water from the cylinder and cold water from the tank. You can add a shower punp if the flow is too weak. You will be able to deliver more hot water, faster, than from an electric shower, especially in winter.

btw are you thinking about using the Aga to heat the cylinder? Would be more economical.

 

[Symptoms]

Flow pressure is the key to choosing the appropriate setup. Get hold of a water pressure test gauge (about £10 to buy from local plumbers merchant, B&Q or Screwfit)) and confirm that you've got sufficient pressure. Most electric shower units do have minimum pressure requirements so it's worth taking the time to check - the gauge will have 3/4" BSP thread to fit to your system (washing machine type connector) so it's not too difficult to do. Remember you've also got to have a separate electrical supply, usually run in 10mm cable (depending on the shower unit) through a dedicated RCCB for safety. Think about fitting a scale inhibitor just down the supply pipe from the shower and always use 'full-flow' isolation (service) valve so as not to restrict water flow.

 

[auldyin]

then you could supply the shower with hot water from the cylinder and cold water from the tank. You can add a shower punp if the flow is too weak. You will be able to deliver more hot water, faster, than from an electric shower, especially in winter.

btw are you thinking about using the Aga to heat the cylinder? Would be more economical.

No problem supplying planned shower with hot water from cylinder but the cold water feed in this bathroom is from what appears to be a separate mains from that feeding the cold water tank. Additionally the cold water tank is some distance away in this old house and it would require major upheaval to link up to this bathroom.

This model of AGA appears only to provide hot water for the rads or for domestic and the choice to provide rads heating was made by the previous owners.