New boiler or leave old unit in place?

twokcc

It won't be difficult to get a condensing boiler with an output high enough to heat radiators but size is determined byyour hot water requirements. A combination boiler can only heat a certain amount of water so if you turn on another hot tap when one already inuse you will get a reduced throput in first tap(or shower). No of showers/baths you have will determine boiler type and size- if youve only got a bath or shower that is likely to be used on its own a combination boiler would be OK. Many combi manufacturers will say that the boiler is capable of suppling great enough hot water for a shower as well. IMO better to have a hot water cylinder and a system boiler- will cost more £ and you need to get the cold water pressure to house checked to see if its high enough. Hot water tank is presurised so shower still get great pressure at shower(which you may not have with your existing system). In my experience you will find that many combination boiler installers don't even suggest a presured hot water system but instead spec a very large combi boiler. This is beacuse they don't have special qualifications to fit a pressurised hot water system so wont recommend something that they can't do. I didn't realise his until went to llook an new build showhouse with bathroom plus ensuite with system boiler and pressurised hot water cylinder. Builders wouldn't be fitting these if the cheaper combi system will do the same job, cylinder takes space but boiler size will often be less than you expect.