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.
Heating emergencies — what to do
If you smell gas, don't use any electrical switches, don't light a flame, turn off the gas supply at the meter if it's safe to reach, and call the National Gas Emergency Service on 0800 111 999 before calling a heating engineer. For no heat or hot water without a gas smell, check the boiler pressure and any error code before assuming a full breakdown.
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.
Common heating engineer jobs
Heating engineers install, service and repair boilers and central heating systems: annual boiler services, fault diagnosis, radiator installation and balancing, powerflushing, and full system replacements. Many also work on unvented hot water cylinders and, increasingly, heat pumps and other low-carbon heating.
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.
Does boiler brand matter?
Established UK brands generally have wider parts availability and more Gas Safe engineers familiar with servicing them, which matters for future repairs, not just the initial install. Ask your engineer which brands they work with most, since familiarity affects diagnosis speed on future call-outs too.
What is a powerflush and do you need one?
A powerflush clears sludge and debris from radiators and pipework using a pumped chemical flush — often recommended if radiators are cold at the bottom or the system is noisy, and standard practice before fitting a new boiler onto an older system so it isn't immediately clogged.
First fix and second fix heating work
On a new build or extension, "first fix" is running pipework to radiator and boiler positions before walls are closed up; "second fix" is fitting radiators, thermostats and the boiler itself once decorating is done. Getting boiler flue routing agreed early avoids conflicts with other trades later.