Boiler Replacement Guide for Cornwall Homeowners

A like-for-like combi boiler replacement typically takes a single day. A system boiler with a new hot water cylinder takes 1–2 days. More complex conversions (e.g., changing from a system to a combi, or adding magnetic filters, flue extensions, or pipe rerouting) may take 2 days. We give a clear timeline during the survey and confirm a date that suits you.

Worcester Bosch offers up to a 12-year warranty on their Greenstar range when installed by an accredited installer (which CCS Heating & Renewables is). Vaillant offers up to 7 years through their Advance installer scheme. Viessmann and Ideal offer 7–10 year warranties on their premium ranges. The warranty length depends on the specific model and your eligibility as an accredited installer customer.

For most off-grid oil-heated homes, a heat pump with the £7,500 BUS grant is now the better long-term choice compared to a new oil boiler. Oil prices are volatile (35–95p/litre since 2021), there is no price cap protection, and oil boilers are expected to be phased out for new installations in coming years. A heat pump running on electricity has more stable costs and can be powered by your own solar electricity. We provide an honest comparison during any survey visit.

A combi boiler provides instant hot water on demand without a storage cylinder — compact and efficient for smaller homes with one bathroom. A system boiler heats water in a separate cylinder — better for larger homes with multiple bathrooms that need high simultaneous hot water flow. Heat pumps require a cylinder and cannot be paired with a combi setup. We advise on the right configuration for your property during the survey.

Yes — a magnetic system filter (such as Fernox TF1 or Magnaclean) is strongly recommended with any new boiler. The filter captures metallic sludge and scale particles circulating in the central heating system, protecting the boiler's heat exchanger. Most manufacturers require a filter as a condition of their full warranty. CCS includes filter installation and system flush as standard with all boiler installations.