In depth
Materials, methods and variations.
Boiler installation is a system engineering job, not a product swap. Brand matters less than sizing, controls, water treatment and commissioning. Here's what shapes our recommendations across Coventry properties.
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Boiler types
Combi: hot water on demand, no cylinder, suits 1–2 bathroom homes with adequate mains pressure (typical CV2/CV6/CV7 stock). System: works with a cylinder, suits 2+ bathroom homes and properties with poor mains pressure. Regular (heat-only): retains an F&E tank in the loft, suitable where wholesale system change isn't appropriate. We size each correctly to the property — not by guesswork.
Brands we install
Worcester Bosch (Greenstar 4000, 8000 Lifestyle, 8000 Style) — strong warranty, widely available parts, premium tier. Vaillant (ecoTEC plus, ecoTEC pro) — quietest in class, excellent reliability, mid-to-premium tier. Ideal (Logic Max, Vogue Max) — strong UK-built option, excellent value with 10-year warranty when registered. Baxi (Platinum, 800) — solid choice on tighter budgets with up to 10-year warranty.
Sizing methodology
Room-by-room heat loss to BS EN 12831 using fabric U-values, ventilation rate and design conditions for the West Midlands. Hot water demand calculated by simultaneous draw-off and DHW recovery rate. We don't oversize — oversizing causes short-cycling, higher bills and shorter boiler life.
What's included in a Boiler Plus-compliant install
From April 2018, every new gas combi install in England must include one of: weather compensation, load compensation, smart controls with automation and optimisation, or FGHR (flue gas heat recovery). We default to smart controls (Hive/Nest/Tado) as the most useful option for most homeowners.
System protection
Powerflush or chemical clean on every replacement install — non-negotiable for warranty validity. Magnetic filter on the return (Adey MagnaClean Pro2 or Spirotech). Sentinel X100 inhibitor dosed to spec. Filling loop fitted properly with double check valve.
Residential vs commercial
Domestic gas boilers up to 70kW we cover routinely. Commercial gas boilers (over 70kW or in commercial premises) require additional COMCAT qualifications — we'll refer to a trusted commercial installer where the job exceeds our scope.