Can a Leaking Radiator Be Repaired?
Spotting a leak from a radiator is understandably concerning, whether it is a small damp patch on the carpet beneath it or a more obvious drip from a valve. The good news is that the majority of radiator leaks are repairable, and full replacement is only necessary in a smaller number of cases where the radiator itself has failed structurally.
Identifying exactly where the leak is coming from makes a significant difference to how straightforward the repair will be. Leaks from valves and joints are generally the easiest to fix, while leaks from the radiator body itself, caused by internal corrosion, are more likely to require replacement.
This article explains the most common points where radiators leak, how each is typically repaired, and what to do in the meantime to limit damage.
Leaks from the valve
One of the most common sources of a radiator leak is the valve itself, either the manual or thermostatic valve on one side, or the lockshield valve on the other. These can leak from the spindle where it enters the valve body, often due to a worn seal, or from where the valve connects to the pipework below. In most cases, tightening the gland nut slightly, or replacing the seal or valve entirely, resolves the issue without needing to replace the radiator.
Leaks from pipe joints
Where pipework connects to the radiator, compression or soldered joints can occasionally develop a slow leak, particularly if they were not seated correctly during original installation or have been disturbed by movement over the years. These joints can usually be re-made or resealed by a plumber without disturbing the radiator itself.
Leaks from the radiator body
A leak appearing from the flat panel of the radiator itself, rather than from a joint or valve, is a more serious sign, usually indicating internal corrosion has worn through the metal from the inside. This type of leak cannot be reliably repaired long-term, since the surrounding metal is likely to be similarly weakened, and replacement of the radiator is generally the recommended course of action.
Leaks from the bleed valve
A leak from the small bleed valve at the top of the radiator is often simply a case of the valve not being fully closed after last being used, or a worn seal within the valve itself. This is usually one of the simplest and cheapest radiator faults to resolve, often requiring only the valve to be replaced.
What to do while you wait for a repair
If a radiator is actively leaking, it is worth isolating it by closing both the valve and the lockshield valve on either side, which stops water flowing into that particular radiator without affecting the rest of the heating system. Place a towel or container beneath the leak to protect flooring in the meantime, and top up the boiler pressure if it drops as a result of isolating the radiator.
How a repair visit typically works
A plumber will first isolate the radiator or the whole system as needed, identify the exact source of the leak, and then either repair the affected valve or joint, or advise on replacement if the leak is coming from the radiator body itself. Repairs are charged at our standard hourly rate of £99 + VAT on weekdays, £120 + VAT in the evening, and £185 + VAT overnight and on Sundays and bank holidays, all excluding VAT, with materials subject to a 20% mark-up on cost.
Choosing a replacement radiator if needed
If replacement is necessary, it is a good opportunity to consider whether the current radiator is correctly sized for the room, since undersized radiators are a common reason rooms never quite feel warm enough. A plumber covering Wimbledon and the surrounding area can advise on suitable replacement options and carry out the fitting as part of the same visit wherever possible.
Need a plumber or heating engineer?
We arrange appointments across Wimbledon and south west London at clear hourly rates. Call 020 3727 2578 or request an appointment.