boiler size for 3 bed end terrace .....

[paulyoung666]

brick cavity construction with cavity insulation , all double glazed , loft insulation , just wondering if a 15kW boiler sounds about right , i know no one can be specific about this , just looking for ballpark ideas of yes or no

 

[doitmyself]

I assume you want a standard boiler, not a combi (instant hot water).

Use the Boiler Size Calculator.

As you have an end terrace, there are two walls side-to-side and one wall front-to-back.

With a well insulated house, you will probably need less than 10kW. But you can't get boilers that small, so go for the next size up, usually 12kW.

The output of boilers is show as a range, e.g 6kW to 15kW. It does not matter if the max is a bit higher than required, but the minimum should be as low as possible below the requirement. This will make the boiler more efficient when it is not so cold.

 

[paulyoung666]

good enough for me , thankyou

 

[dontknowitall]

A reasonably quick and fairly accurate way is to calculate heat required for each room:

Length x width x height in metres. Then this figure times 45 divided by 1000. This will give you the watts required for each room (and size of radiator required for that room as well). Add them all up, add a little for hot water and luck and you should get an appropriate figure for the boiler required.

Eg. room 3m x 2.5m x 2.8m = 21 x 45/1000 = 0.945 so 1Kw radiator required.

 

[Rodreguez]

jus had a go at boiler calc got a 3 bed end terrace jus had cavity wall filled but front and back are timber frame but downstairs i put celetex in, doubled glazed and got over 75mm loft insualtion. i put unfilled cavity in and came out at 9.34kw and from experience i know this is under sized