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.
Heating regulations, FAQ
Do I need Building Regulations sign-off for a new boiler? A Gas Safe registered engineer self-certifies this as part of the installation. Can I service my own boiler? No — servicing a gas appliance legally requires a Gas Safe engineer. What if my installer isn't Gas Safe registered? The work is illegal and any certificate issued isn't valid.
Gas safety duties for landlords
Landlords must have a valid Gas Safety Certificate (CP12) renewed every 12 months for any gas appliance in a rented property, and provide a copy to tenants. It's a legal requirement, and letting agents/insurers routinely check for it — failing to have one can invalidate insurance and result in prosecution.
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.
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.
When to replace vs keep existing radiators
Radiators themselves rarely need replacing unless damaged, corroded, or you're changing the property's heat demand (e.g. adding a heat pump, which often needs larger radiators to run at a lower temperature). A power flush can often extend a radiator's working life significantly cheaper than replacement.
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.
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.