Pressure tank or Megaflow???

[biojem]

I've bought a house that needed refurbishment. Before it only had a bath and I want to add a shower to that main bathroom and add an ensuite downstairs.

I noticed the hot water was not very strong and so we checked the flow rate and pressure. The pressure is 4 bar which I assume is quite good. The flow rate is 14 litres per minute. The house is a four bedroom two bathroom house.

The current boiler is a vailient eco pro 24 which I assume I will need to upgrade. The question is, is whether to fit an accumulator tank along with a new more powerful combi or is it possible to fit a conventional boiler along with a mega flow to get the better pressure for the two bathrooms?

Any advice gratefully received!

 

[D_Hailsham]

Which tap did you use to measure the flow rate and pressure? If in the kitchen, some taps restrict the flow. Better to use the garden tap.

Installing a larger diameter feed pipe into the house will increase the flow rate.

You need at least 20 litres/min if you want to use two showers at the same time. That would mean at least a 35kw combi boiler.

If you install a conventional (non combi) boiler, you size it for the central heating requirement and add a few kW for the HW cylinder. Use Whole House Boiler Size Calculator to find out what size boiler you will then need.

As you are carrying out a refurbishment, make sure you insulate as well as possible. It will means a smaller boiler and lower running costs.