New boiler advise sought

[hamazz]

hi

currently have a old conventional ideal mexico super cf4140 boiler, which is rated at about 50kw,
looking to replace with a new combi, was advised that size needed is a 24kw?? checked on http://www.idhee.org.uk

4 bed semi detached with solid walls, double glazed and 2 bathrooms, 2 toilets,


any advise what to look for, am aware will need to strip out the tanks in the loft and water heater, and need a bit of re-plumbing, and rough idea of costings, am based in nw london

hamazz

 

[Agile]

To convert to a combi is probably not a good idea but would cost about £2000-£4000

You seem to have had some very bad advice. Probably from a boiler installer whose only interest is his!

Tony

 

[Dan Robinson]

Think you mean 50000 BTU. Not 50kw

Have a search of the site...this has been done to death.

 

[hamazz]

on the spec from ideal it says 50.1kw (170 900 btu/h)

well the boiler is over 10years old, so might be an idea to get it changed, its energy rating is D, so was thinking of putting a new one in, i got a mate that can do most of the re-plumb and stripping and i can get another one in for the gas side of things, should costs should be a bit lower

hamazz

 

[CBF]

it sounds like your orginal boiler was way over sized 50kw in a domestic house wow, a 24kw combi is nearly as crazy an idea as the orginal boiler, with two bathrooms i wouldn't think of installing a combi at all

 

[ALEC1]

its very common for old boilers to be over sized.. for some reason people think it is good to have more kws...the average London HOUSE is probably only 30kws tops..

many times I find my self specifying for hot water storage performance rather than house size...and of course with compensation controls you can match the the out put to both the house and the cylinder...

 

[Dan Robinson]

I'd be surprised if the OP needed anything much beyond 18kW. They also need to be certain a combi would provide enough hot water.