Leak under the sink in Macclesfield

Start by drying everything and working out where the water is coming from, because water travels along pipework and drips off the lowest point, which is rarely where it escaped. Line the cupboard with kitchen roll, run the tap for thirty seconds, then look. Then fill the bowl and let it drain, and look again. Those two tests separate a supply leak from a waste leak, and that is most of the diagnosis done.

Waste leaks are the most common. The trap under the bowl unscrews by hand, and the usual culprits are a perished washer, cross-threaded connectors, or a trap that has been knocked out of alignment by everything stored in the cupboard. Bottle traps in particular loosen over time. If the leak only appears when the washing machine or dishwasher drains, the appliance hose spigot on the trap is where to look.

Supply leaks are more urgent because they run continuously at mains pressure. Flexible tap connectors — the braided hoses feeding modern mixer taps — are a known failure point, and when one bursts it does not drip, it sprays. They have a service life, and one that shows rust staining or bulging under the braid should be replaced before it goes rather than after. The small isolation valves below them also weep at the spindle as they age.

The reason this job is worth doing properly rather than wrapping in tape is what sits underneath: chipboard carcassing, which swells and crumbles once it is wet, and often a floor void below that. A slow drip under a kitchen sink can destroy a base unit and the flooring under it long before anyone notices, because nobody looks in that cupboard for months at a time.

While the plumber is under there, it is worth having the isolation valves checked and replaced if they are stiff. They are what lets the next repair — a tap washer, a new mixer, an appliance swap — happen without turning the whole house off, and they cost very little to fit while the cupboard is already empty.