Need Help deciding Which System is Best for New House

[moosekat]

Hi guys,
We are in the midst of buying a 1930s house at the moment, and one of the things we are looking to do is to turn the dining room into a kitchen diner, and split the kitchen into a utility room / shower room. To do this, we will need to move or replace the existing boiler.
All other houses I have owned have had combi boilers. As they have been 1 bathroom 3 bedroom houses, we have never had much issues with it. But now that we are moving into a 4 bedroom 2 bathroom house, what is the best option to go with? I hate the idea of running out of hot water (fond memories from my in laws house) that you can get with a hot water tank, but I really want to have enough pressure and water to possibly run 2 showers at once. I know that they all have pros and cons, but it seems to be such a minefield!! Also at the moment the hot water tank is taking up a large part of space in my sons to be bedroom. we would love to get this space back too!! I also do not think that there is a cold water tank in the loft.. Also I am not a massive green freak, but I want to try and be as eco friendly as possible too (hopefully cheaper in the long run!!)!! There are approximately 11 or 12 rads in the house.

Any help and advice would be greatly appreciated.

Thanks

Nick

 

[D_Hailsham]

I really want to have enough pressure and water to possibly run 2 showers at once.

So you need a flow rate of at least 20 litres/min with a dynamic pressure of 1.5bar or more.

This would require a 50kW combi boiler!

The alternative is an unvented mains pressure HW cylinder, which can be installed anywhere convenient. A 210 litre should be more than adequate.

This would still require the same flow rate/pressure as a combi but the boiler would only need to be about 20kW, which should be more than adequate for the central heating as well. Use the Boiler Size Calculator to find the heating requirement of your house.

You need to measure the incoming cold water flow rate and dynamic pressure before deciding what to do.