Carbon monoxide safety
A carbon monoxide alarm should be fitted near any gas appliance, and tested regularly like a smoke alarm. Signs of a potential CO issue include a yellow/orange (rather than blue) gas flame, soot marks around an appliance, or unexplained headaches/nausea that ease when you leave the property — treat these as urgent.
Combi vs system vs conventional boilers
A combi heats water on demand with no tank or cylinder, suits smaller properties with one bathroom. A system boiler uses a hot water cylinder but no cold water tank, better where several taps might run at once. A conventional (regular) boiler uses both a tank and cylinder, common in older or larger properties, or where mains pressure is poor.
Gas fires and stoves — same Gas Safe rule applies
Installing or servicing a gas fire, gas stove, or gas oven/hob is gas work under the same legal framework as a boiler — it must be done by a Gas Safe registered engineer qualified in that specific appliance category, not just any gas-qualified engineer, since categories are appliance-specific.
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.
Common heating myths, busted
"Leaving heating on low all day is cheaper than on/off" — not reliably true; it depends on the property's insulation and the specific system. "A hissing boiler just needs bleeding" — hissing more often points to a pump or valve issue than trapped air. "Bigger boiler means faster hot water for everyone" — it's more about cylinder size and flow rate than boiler output alone.
Electric boilers, pros and cons
Electric boilers avoid combustion entirely (no flue, no CO risk, no Gas Safe requirement) but electricity typically costs more per unit than gas, so running costs can be higher for the same heat output. They suit smaller properties or as a backup rather than being the default choice for most UK homes.
Air source heat pumps, what to know
A heat pump extracts heat from outside air even in cold weather, and typically runs at a lower flow temperature than a gas boiler, which usually means larger radiators or underfloor heating for the same comfort level. Installation is a bigger job than a boiler swap and government grant schemes (like the Boiler Upgrade Scheme) can offset some of the cost.
Frozen condensate pipes in winter
A frozen condensate pipe (the small plastic pipe draining from a condensing boiler, often outside) is one of the most common winter boiler breakdowns — it causes the boiler to shut down as a safety measure. Pouring warm (not boiling) water over the pipe to thaw it, if safely accessible, sometimes fixes this without a call-out.