Help with new boiler and future shower

[CPdiyer]

Hi
Having a new boiler fitted soon in a standard 3 bed home, going for a standard combi probably Worcester or Valiant 30kw - however in the future I will need a new bathroom and love great powerful showers, I have read you need a cylinder for water with a pump to achieve this.

I dont want to fit a boiler that is not suitable.

Am I trying to reinvent the wheel, would it be simpler to use a thermostatic mixer valve and run off the combi directly? maybe spend more on the combi.

Thanks in advance.

 

[ianmcd]

depending on the water flow rate in your property you can get a great shower rate with a combi, but again if you have the flowrate you can have a system boiler with an unvented HW cylinder which doesnt need a pump, all dpends on how good your water supply is

 

[Madrab]

Get your mains pressure and flow checked and then if you have the capacity and the space then an un-vented cylinder is the direction I'd be looking towards for a family home.

 

[CPdiyer]

I will be replacing the existing incoming lead water main with MDPE at the same time - so I don't see mains flow or pressure being an issue.
So I should be ok with a combi - but better with un-vented and system boiler (not familiar with either)
Any suggestion on size on both?

 

[Madrab]

A combi will give you a mains pressure shower, yes ... adequate pressure, flow and boiler size not withstanding but the minute someone else opens a hot tap, then game's a bogey

 

[Madrab]

All depends, At least 11L/min hw output from a combi for a full on shower. Everyone's full on is different tho.

Unvented hot water depends on the usage, for your size of house start at around 160L and go up depending on number of people and frequency of use.

Always get a well recommended GSR CH engineer in to give you some advice on what your options are.