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.
Protecting pipes in cold weather
Pipes in unheated spaces — lofts, garages, outbuildings — are the most common source of a winter burst pipe once temperatures drop below freezing for a sustained period. Lagging exposed pipework and keeping heating on a low constant setting during a cold snap, rather than off, are the two most effective preventive steps.
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.
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.
Plumbing regulations, FAQ
Do I need a certificate for a new bathroom? There's no single certificate like Part P for electrics, but any work must comply with Water Fittings Regulations, and gas-connected work needs a Gas Safe engineer. Can I do my own plumbing? Straightforward repairs, yes; anything affecting the public water supply (like a new connection) should go through a WaterSafe-approved plumber.
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.
Plumbing in a washing machine or dishwasher
Both need a cold water supply, a drain connection, and in most cases their own isolation valves so they can be disconnected without turning off water to the whole property. Using a shared valve with another appliance is a common shortcut that makes future repairs more disruptive than it needs to be.
Combi vs system vs conventional boilers
A combi boiler heats water on demand with no separate tank, suits smaller properties with one bathroom. A system boiler uses a hot water cylinder but no cold water tank, better for higher demand. A conventional (regular) boiler uses both a cylinder and a tank, common in older properties and useful where mains pressure is poor.