Worcester Bosch 18kw boiler

For a typical UK 4-bed with 8 rads, an 18 kW system boiler is big enough for both heating and a 210 L unvented cylinder. If you want faster hot-water recovery (e.g., lots of back-to-back showers), step up to ~24 kW only if the cylinder coil can absorb it; otherwise you gain nothing. *however this is all based on best case scenarios eg correct levels of insulation and so on.

Dear Customer I believe you are referring to a system/regular 18 kw boiler. Yes this would be sufficient if it’s an existing installation. Hope this helps. Thank you