Home plumbing knowledge base

The internal stop tap is usually near the point where the mains supply enters the home, often under the kitchen sink.

Do not force a seized stop tap; arrange a plumber and ask the water supplier about the external stop tap if isolation is urgent.

Low pressure can reflect peak demand, a partly closed stop tap, a local plumbing fault or the supply; compare outlets before calling the water company.

Pressure is the force available to move water; flow rate is the volume delivered in a given time.

Yes: with every outlet and water-using appliance off, movement at the meter suggests water is still passing into the property.

Turn off the water, open the affected tap and thaw the pipe slowly with gentle warmth; never use a naked flame.

Banging can come from loose pipework, faulty valves, trapped air or pressure shocks when flow stops quickly.

A dripping overflow normally means a cistern is filling above its intended level because its inlet control is not shutting off.

Compare taps and test a glass away from the sink; the cause may be the drain, household plumbing, an appliance or the wider supply.

Homes built before 1970 may have lead pipework; check near the internal stop tap and ask the water company to test if you are unsure.

Use freshly drawn cold water from the kitchen mains tap for drinking; a bathroom cold tap may be supplied from a storage cistern.

Do not block or adjust the discharge; stop using the heat source if safe and contact a competent unvented-hot-water engineer.

Water running into the bowl usually means the cistern is overfilling or the flush valve is not sealing.

A drain smell can come from debris, stagnant water, an empty or siphoned trap, a poor appliance-waste arrangement or a drainage fault.

A water fitting approval can show that a product meets a relevant quality standard, but installation and intended use still determine compliance.

An outside tap needs backflow protection suited to how it is used; a double check valve is not sufficient for every hosepipe risk.

A radiator that is warm below but cold at the top commonly has trapped air and may need bleeding when the system is off and cool.

A radiator that is warm at the top but cold below commonly points to sludge, debris or restricted circulation rather than trapped air.

The numbers on a TRV are relative room-temperature settings, not identical temperatures across every make and model.

Some proposed plumbing work must be notified to the local water undertaker before it starts; ask the undertaker or use an approved contractor.