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.
Three steps to hiring the right heating engineer
First, confirm Gas Safe registration and ask to see the ID card, which lists exactly what gas work they're qualified for. Second, get a written quote naming the boiler model. Third, ask what the manufacturer's warranty requires (usually an annual service) to keep it valid.
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.
Shared heating systems in flats and conversions
Some converted properties share a communal boiler or heating system rather than each flat having its own — check which applies before booking, since a fault or upgrade on a shared system usually needs freeholder or management company involvement, not just your own arrangement.
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.
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.
Boiler installation certificates, explained
A new boiler installation legally requires a certificate under the Gas Safety (Installation and Use) Regulations 1998, issued by the Gas Safe registered engineer who did the work. You'll need this when you sell the property, and some insurers ask for it if you make a claim involving the heating system.
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.