What a good heating quote should include
A proper quote should specify the boiler make and model (not just "a combi boiler"), whether a powerflush is included, the warranty length, and what certificate you'll receive on completion. If a quote is missing the boiler model, ask before agreeing.
Boiler warranties and workmanship guarantees
Manufacturer warranties on new boilers commonly run 5-10 years, but usually require annual servicing by a registered engineer to stay valid — check whether it has to be the same installer or any Gas Safe engineer. This is separate from any workmanship guarantee the engineer offers on their own installation work.
Boiler cover and service plans
Separate from a manufacturer's warranty, some homeowners take out an annual boiler cover plan (often through an energy supplier) that includes servicing and breakdown cover. Worth checking what's already included in a recent warranty before paying for overlapping cover.
Why an annual boiler service matters
An annual service checks for gas leaks, correct combustion, and general safety, and most manufacturer warranties require it to stay valid. It's also when a heating engineer is most likely to catch a developing fault — a failing part or a a pressure issue — before it causes a breakdown, particularly in winter when boilers are used hardest.
Understanding the labour vs materials split
The boiler itself is often the largest single cost, but labour, flue work, and any additional pipework or radiator changes add up. If a quote looks cheap, check it specifies the same boiler tier (entry-level vs mid-range) as a competing quote, not just a lower labour charge.
What affects the cost
Cost depends on the type of system (combi vs system vs conventional), whether it's a straightforward swap or a full system change, boiler brand and output size, and property access. Moving a boiler's location, rather than replacing it in place, adds cost because of the extra pipework, flue routing and making good involved.
Why Gas Safe registration is a legal requirement
Anyone installing, servicing or repairing a gas appliance or gas pipework in the UK must by law be on the Gas Safe Register, which replaced CORGI in 2009. This covers boilers, gas fires and gas cookers. Using an unregistered engineer for gas work isn't just risky, it's illegal, and any resulting certificate isn't valid.
What a boiler fault code usually means
Modern boilers display a fault code rather than just stopping — the exact code varies by manufacturer, but common causes include low pressure, a faulty sensor, an ignition fault or condensate pipe freezing in cold weather. Note the code and the boiler make/model before calling; it speeds up diagnosis considerably.