Finding a hidden leak
A leak inside a wall or under a floor isn't always obvious until it shows as a damp patch or a high water bill. Plumbers use damp meters, thermal imaging or (for harder cases) tracer gas to locate a hidden leak without having to open up an entire wall speculatively — worth asking about before agreeing to exploratory work.
Hard water and your plumbing
In hard water areas, limescale builds up inside pipes, taps, showerheads and boiler heat exchangers over time, gradually reducing efficiency and flow. A plumber working in a hard water area may recommend a water softener or scale inhibitor as part of a boiler installation, particularly for a system that's expected to last 10+ years.
Three steps to hiring the right plumber
First, check they're registered with a WaterSafe scheme (or Gas Safe too, if the job needs it) and ask for the registration number. Second, get a written quote that separates labour from parts. Third, ask what happens if the job uncovers a bigger problem — a good plumber will tell you before continuing, not after.
What affects the cost
Cost depends on the scope of the job, how accessible the pipework is (under a floor vs behind a wall), whether parts need to be sourced specially, and whether the job is planned or an emergency call-out. A simple tap or valve replacement is usually quick and low-cost; anything requiring pipework to be rerouted, or walls/floors to be opened up, costs more partly because of the making-good work afterwards.
When plumbing work needs a Gas Safe engineer instead
Plumbers can install and repair most water systems, but any work on a gas appliance or gas pipework — a boiler, a gas fire, a gas hob — is illegal for anyone who isn't on the Gas Safe Register, by law. If a job involves both plumbing and a gas connection (moving a boiler, for example), check whether your plumber is also Gas Safe registered before booking.
Water-based underfloor heating, what's involved
Unlike electric underfloor heating, a water-based system runs off your boiler via a manifold and needs the floor buildup to accommodate the pipework — usually easier to fit during a renovation than retrofit into a finished floor. It's often paired with a lower-temperature heating setup than radiators use.
Common plumbing jobs
Plumbers handle everything from a dripping tap to a full bathroom re-pipe: fixing leaks, clearing blocked drains, replacing taps and valves, fitting new bathroom suites, repairing or replacing radiators, and connecting appliances like washing machines and dishwashers. Emergency work (burst pipes, no hot water) is usually handled separately from planned jobs like a bathroom refit.
What is a power flush and do you need one?
A power flush clears sludge and debris from a central heating system's radiators and pipework using a pumped chemical flush — usually recommended if radiators are cold at the bottom, or before installing a new boiler onto an older system, so the new boiler isn't immediately clogged by old sludge.