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.
Shared water supplies in flats and conversions
In a converted property, check whether your flat has its own independent stopcock and supply, or shares one with other flats via a communal system. A shared supply can mean a repair affects your neighbours too, and sometimes needs freeholder involvement before work starts.
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.
First fix and second fix plumbing
On a new build or extension, "first fix" is running pipework through walls and floors before they're closed up; "second fix" is fitting the visible taps, radiators and appliances once decorating is done. Timing this with other trades on site matters — pipework needs to be pressure-tested before it's covered over, not after.
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.
Plumbing and selling your home
Buyers' solicitors sometimes ask about the age and condition of the boiler and any recent plumbing work, particularly if there's visible evidence of a past leak or repair. Keeping paperwork for any significant plumbing work — a new boiler, a bathroom refit, a burst pipe repair — makes this a much smoother conversation.
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.