- 18 Oct 2007
- Reaction score
Even worse is sizing the boiler to match possible oversized rads. This is easily possible if the insulation of the house has been improved.sizing a boiler to match possible undersized rads is quite literally the stupidest thing I have ever heard.
That's what I said earlier.size the boiler for the heatloss of the house plus any extra you think you may need for hot water or any future extension.
Very sensible advice, but few installers thinks about it. Considering that a boiler runs for most of the time below the calculated output, the lower a boiler can modulate, the better. It's a pity other manufacturers don't follow the example of Geminox, who produce boilers which can modulate between 1kW-10kW or 2kW-17kW.also find a boiler that has a good modulation range that can meet your needs.
for example if the heatloss comes out at 15kw then a boiler that can go from 4kw-30kw is better then one that can only range of 9-16kw...
To the OP
You can find the output of your radiators by using the Stelrad Elite Catalogue.
If the rads add up to less than the calculated boiler size, you have a choice: Install more/larger rads or put jumpers on when it gets very cold. If, on the other hand, the rads add up to more than the calculated size, you dont' have to do a thing. It just means that you will be able to run your boiler at lower temperatures.