Radiator leaking

Is the leak spreading or near electricity?

Describe the wet point without touching it

This guide concerns water-filled central-heating radiators. Electric radiators, electrically heated or dual-fuel towel rails and unfamiliar shared systems need their maker/operator’s advice. From a dry safe place, report the first visible wet area if already known. If you only see a puddle, report the source as uncertain: water can run down from above or along a surface. Do not wipe a hot fitting or wrap tissue around it to diagnose a leak.

Pipe, connection and valve are useful location words

The radiator body holds heating water; the connected pipes, joints and valves form part of its heating circuit. Body leakage, a pipe connection and a top vent need different assessments. Tell the engineer the visible location, rather than deciding that every wet radiator needs the same valve repair.

What can you do without opening the system?

1. Start from a dry safe place

   Keep people clear of hot metal/water and wet electrical equipment. If access is wet, the leak spreads or inspection would need touching fittings, stop and obtain suitable urgent help.

2. Contain only a small safely reachable drip

   If a stable bowl/container can be set directly below the drip, or towels placed on the floor, without approaching hot water/electrics or touching the radiator, use them to limit spread. Do not tuck bags behind the radiator, wrap fittings or move the unit. Watch only from the dry position; do not handle a full hot container.

3. Record what is already apparent

   Note body/edge, valve, joint, top vent or “unsure”, whether it is active or a recurring stain, recent work and any already visible pressure warning. A photo from the same dry position can help. Do not run heating, bleed or top up pressure to test it.

4. Arrange assessment and monitor the safety boundary

   Contact the landlord/operator or suitable heating engineer. If containment is failing, water spreads or approaches electrics, keep clear and make the request urgent. A dry-looking patch at one moment does not prove the problem is repaired.

Why the stopcock or TRV may not stop this leak

The home’s incoming mains stop tap controls incoming water, not every heating-water circuit. A radiator circuit still contains water, and its supply arrangement may be sealed or supplied from stored water. This guide therefore does not give a mains-stopcock procedure as radiator isolation. Likewise, normal heating off removes a heating request; it is not a verified hydraulic shut-off. If the leak continues, arrange help rather than searching for more valves or topping the pressure up.

A TRV is a room-temperature control, not a guarantee that all routes to a leak are closed. British Gas warns that it may reopen in cold conditions. A leak can also be on a valve or connection outside the radiator itself. Do not remove heads/caps, adjust a lockshield or assume both ends are safely isolated from a generic online diagram. The engineer must establish the actual arrangement and appropriate isolation before repair.

A leak location does not settle the repair

Body metal weakened by corrosion, a valve/seal fault, a connection and an air-vent problem call for different work. Rust or a wet edge does not establish the cause on its own. Ask the engineer what was found and whether the remedy is a fitting repair, radiator replacement or wider-system work. Do not use tape, paste, leak sealer or patch kits as a guessed fix; this page supplies no tightening, draining, bleeding or refilling procedure.

What should the quote and repair check cover?

Tell the engineer which radiator, visible wet location or uncertainty, whether water is spreading, recent work, stains/recurrence and any known pressure warning. State whether you used a normal heating-off setting and that no radiator fittings were altered. Check any warranty/service cover and contact the installer if this began after work. In rented or managed accommodation use the landlord/operator route.

Ask whether attendance/fault-finding is included, what actual fault was found, whether the work is one fitting, one radiator or wider system work, and whether parts, labour, VAT, drain/refill requirements and a return visit are included. There is no verified comparable all-in price here. After professional repair, ask how they checked the original leak location during normal operation, whether system pressure/restoration needs further attention and when you may resume heating. If water or the original recurring stain returns, report it rather than tightening or topping up yourself.

Questions about a leaking radiator