Common Plumbing Problems and When to Call a Professional

Dripping taps

A single dripping tap is not going to flood the house, but it will run through more water in a year than most people expect and it usually points at a worn washer, cartridge or o ring. On a modern quarter turn tap the fix is a cartridge swap. On a traditional compression tap it is a washer.

DIY or call. A confident homeowner with basic tools can change a washer or a cartridge, provided they can isolate the water at the tap or at the property stopcock. If the isolators are seized or the tap is chrome plated brass on soft mains pipework, stop before you snap a fitting. That is when a small job turns into a big one.

Running or hissing toilets

A toilet that keeps refilling by itself, or hisses quietly for hours between flushes, is almost always a failed inlet valve or a warped flush valve seal in the cistern. It is one of the most common wasters of water in the home and typically an easy fix.

DIY or call. If you are comfortable turning off the isolator, lifting the cistern lid and swapping a fill valve, you can save yourself a callout. If the toilet is close coupled to the pan and needs the cistern lifted off, or if the isolator is stuck, book someone. A cracked cistern from over tightening a bolt is expensive to replace.

Blocked drains

The most useful first step with any blockage is to work out how far downstream it is. If just one basin or bath is slow, the blockage is local, probably in the trap. If every fitting on the same floor is slow at once, the problem is further along, in the branch or the main stack. If waste is backing up out of a downstairs fitting when you flush upstairs, the drain outside has almost certainly failed and the risk is a much bigger mess.

DIY or call. A plunger and, on a slow basin, cleaning the trap is fair game. Chemical drain cleaners are a poor idea in most cases: they can damage older pipework and they rarely clear anything a plunger cannot. Anything that involves lifting a manhole cover, or where waste is backing up, is a call.

Low mains pressure

Low pressure can be a nuisance or a real problem depending on the property. On a mains fed system, common causes include a partially closed stopcock, a failing pressure reducing valve, a partial blockage on a strainer, or a wider issue on the incoming main. On a stored system with a header tank, symptoms often trace back to airlocks or tank issues.

DIY or call. Check the property stopcock is fully open. Check any isolators feeding the tap or fitting you are worried about. If the stopcock is fine and everything else in the property is affected, it is time to bring someone in with pressure and flow test kit rather than guess.

Radiator issues

Cold at the top of a radiator usually means trapped air, and bleeding solves it. Cold at the bottom of a radiator usually means sludge, and bleeding does nothing at all. A radiator that is entirely cold, when the boiler is on, is either shut off at the valve, airlocked, or has a stuck thermostatic head that thinks the room is already warm.

DIY or call. Bleeding radiators is a homeowner job with a bleed key and a rag. If the same radiator needs bleeding every few weeks, that is a sign of air ingress somewhere in the system and needs investigation. Anything involving removing a radiator to flush it, or working on a stuck thermostatic valve, is safer left to a plumber.

No hot water

Loss of hot water on a combi boiler almost always points at the boiler itself, whether that is a fault code, a pressure issue or a diverter valve. Loss of hot water on a stored system usually points at either the boiler heating the cylinder or, on an unvented cylinder, an immersion or thermostat problem.

DIY or call. Check the boiler is on, the system pressure is in the green, and the timer or app is asking for hot water. Beyond that, boilers and unvented cylinders are jobs for a Gas Safe or G3 qualified engineer respectively. Removing panels, isolating gas or unscrewing valves on an unvented cylinder is not for the DIY toolkit.

Leaks

Any leak, however small, is on the clock. Water is patient. It finds joists, ceilings and cables and it does damage that surfaces months later as staining or as an electrical trip. If you find a leak the first job is to isolate the water. Every home should have a known, working stopcock. If yours is buried, seized, or unlabelled, sort that out on the first dry day.

DIY or call. Small compression joint tightens or a burst hose to a washing machine that can be isolated are homeowner territory. Anything soldered, hidden in a wall or under a floor, or leaking from a heating system that is holding pressure, is a call.

Emergency, or bookable

Not every plumbing problem is an emergency, and treating one as an emergency when it is not gets you a bigger bill for no better result. The rough test we use with customers:

• Emergency. Uncontrolled leak, gas smell, no heat in the property in winter with a vulnerable occupant, sewage backing up, hot water discharging from a tundish that will not stop, boiler with a fault that cannot be reset safely.
• Bookable this week. Slow leak that can be contained, one radiator not heating, dripping taps, running toilet, one blocked fitting, low pressure.
• Bookable at your convenience. Annual services, planned upgrades, and cosmetic issues that are not leaking or unsafe.

The homeowner's toolkit

You do not need to become a plumber to look after a home. Four things save a huge amount of grief:

• A working, labelled stopcock and a working stopcock on every washing machine, dishwasher and outdoor tap.
• A modest tool kit: adjustable spanner, radiator bleed key, plunger, PTFE tape, torch and a bucket.
• A written note of when the boiler was last serviced, when the cylinder was last serviced, and when the gas safety check is due.
• The phone number of a plumber you trust, saved before you need it.

Everything else you can look up in the moment. The point is not to fix every problem yourself but to know what is happening, catch things early, and make sensible calls about when to pick up the phone.