I've done the Myson heat loss calculation and the heat loss is 13840 W.
The calculation tells me I need a boiler output of 22.55 kW.

The B&Q "Installing a gas fired central heating system" leaflet says just
add 10% to the heat loss to calculate the required boiler output.

Why the 63% extra for the Myson calculation?

Wickes rads seem fairly cheap. Anyone know of a better source with
discounts for bulk?

Thank you,

Neil