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.
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.
Plumbing emergencies — what to do first
For a burst pipe or major leak, turn off the water at the stopcock (usually under the kitchen sink or where the supply enters the property) before calling anyone — this limits water damage while you wait. For no hot water or heating, check the boiler pressure gauge first; a common cause is low pressure, which some homeowners can safely top up themselves via the filling loop.
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.
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.
Aftercare after plumbing work
After a boiler installation or bathroom refit, you should receive a benchmark/commissioning checklist (for a boiler) or a written summary of the work done, which you'll want if you make an insurance claim or sell the property later. Keep it with your household paperwork alongside any appliance warranties.
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.
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.