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.
Connecting new kitchen appliances
A new dishwasher or washing machine needs its own isolation valve and a suitable waste connection — if you're changing from an old appliance in a different position, this sometimes means new pipework rather than just reconnecting to the old point.
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.
Boiler pressure and heating faults
Most combi boilers run best between 1 and 1.5 bar of pressure — too low and the heating cuts out, too high and the pressure relief valve can discharge. A plumber checking a heating fault will usually look at pressure, check for trapped air in radiators (bleeding), and check the pump and diverter valve before assuming a full boiler fault.
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.
Immersion heaters and hot water cylinders
An immersion heater is an electric backup for heating water in a cylinder, useful if the boiler fails or as the main hot water source in an all-electric property. If yours is tripping the electrics or not heating water, it's sometimes the heating element itself rather than the boiler or cylinder at fault.
Seasonal plumbing checks worth doing
Before winter: check outside tap isolation valves, and consider draining down any external pipework not in regular use. Before summer: check garden irrigation and outside tap connections for wear, since these see much more use once the weather turns. A five-minute check avoids most seasonal callouts.
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.