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.
What WaterSafe registration means
WaterSafe is the umbrella body for the UK's Approved Contractor Person schemes (including APHC, CIPHE, WIAPS and SNIPEF). A WaterSafe-approved plumber has been assessed on their knowledge of the Water Fittings Regulations, which exist to stop poor installation work or substandard products contaminating the drinking water supply — not just general plumbing competence.
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.
Outside taps and garden plumbing
An outside tap needs its own isolation valve and, in colder areas, either an internal shut-off you can drain down for winter or a proper anti-frost design — a poorly installed one is a common cause of a burst pipe in cold weather. This is separate from the electrical requirements for any pond or irrigation pump also being installed.
Plumbing responsibilities for landlords
Landlords are responsible for keeping water and heating systems in safe working order, and if there's a gas boiler, a valid annual Gas Safety Certificate is a legal requirement, not optional. A burst pipe or heating failure in a rented property is generally treated as an emergency repair the landlord must address promptly.
How many quotes should you get?
Three is a reasonable number for most plumbing jobs — enough to spot an outlier without asking too many people to visit for a straightforward repair. For a planned job like a bathroom refit, make sure each quote covers the same scope, since a lower price sometimes means less is included, not better value.
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.
How plumbing quotes work
Describe the job, including whether it's an emergency, a planned repair, or a full installation, and mention access — under a suspended floor is very different from behind fitted units. Plumbers use this for an initial estimate; the final price is usually confirmed once they've seen the fault or the space in person.