How to Fix a Leaking Radiator
Leaking radiators can be both frustrating and harmful to your home, but what many don’t realize is that the problem can often be fixed quickly and at minimal cost. First and foremost, stay calm! To avoid a mess, place some old towels underneath the leak to catch and soak up any water, this will buy you time to assess the situation and figure out the best solution.
Common Causes of a Leaking Radiator
Common causes of a leaking radiator include:
Loose or damaged valves: The radiator's inlet or outlet valves may become loose or worn, leading to leaks around the valve connections.
Faulty radiator seals or joints: The seals between sections of the radiator or at the valve joints can degrade or become faulty, resulting in leaks.
Damaged bleed valve: If the bleed valve (used to release trapped air) is not tightened properly or becomes worn, water can escape.
High water pressure: Excessively high pressure in the central heating system can cause leaks at weak points in the radiator or its connections.
Loose pipe connections: Pipes connecting the radiator to the heating system may loosen over time, leading to leaks around the fittings.
Fundamentally, whilst radiators can leak from just about anywhere, it is commonly the valves, where they join, around the bleed valve, or on edges or corners where the welding may have deteriorated that are the causes.
A less common cause of a leaking radiator is corrosion on the radiator itself. As with anything, things get old resulting in a natural degradation, particularly when water and metal are involved. Though this is typically reserved for old radiators, it is still something to consider if your system is an old one.
First Things First, Locate the Source of the Leak
>>> Make sure to do this whilst the heating is off and the radiator is cold! <<<
Use a towel or some kitchen roll to dry the surface of your wet radiator thoroughly. It's hard to locate the source of a leak when the radiator is soaked, so drying it will make it easier to identify the problem. Once the radiator is dry, you should be able to spot the leak more easily. Take some toilet tissue and check each fixture or joint on the radiator one at a time; this should allow you to pinpoint where the leak is coming from.
Radiator Body Leak
Leaks from the radiator body are typically known in the trade as 'pinhole leaks', and are commonly caused by a build-up of sludge which if left untreated will build up over time. This sludge build-up effectively rots the radiator from the inside out and causes very small leaks, hence the name - 'pinhole'.
Unfortunately in the event of pinhole leaks, you’ll need to turn off both of the valves connecting to the radiator and get yourself a new radiator. It may also be worth renewing the valves at the same time which you can also get from us.
Leaking Radiator Valve
Should you discover that you have a leaking radiator valve this can often be a simple issue to fix. Typically, a leaking radiator valve is a result of wear or damage to the internal spindle packing. This leak only occurs when the valve is partly open and will stop when the valve is closed.
Repairing a Leaking Radiator Valve
Drain the system below the leak.
Close the valves - both the supply valve and the lockshield valve. Make note of how many turns it takes to close the lockshield valve, as this will be the required number of turns (in reverse) to open it again.
Put down towels or old rags to catch any excess water that escapes.
With an adjustable spanner undo the union nut
Undo the bleed valve and drain any remaining water from the radiator.
Wrap the valve tail in PTFE tape starting at the male end.
Re-tighten the union nut & open the bleed and lockshield valves (remembering how many turns it took to close).
Allow the radiator to fill up with water and check for leaks.
Close the bleed valve.
If this doesn’t stop the leak, you may need to replace the valve. The important part is to ensure the new valve matches your current one as a different kind may not align with your existing pipework. Unsure of where to begin? Check our guide to radiator valves, as well as our guide for changing radiator valves.
Leaking Radiator Spindle
The spindle of a radiator is the connection between the pipework and the radiator itself and can often leak if loose or damaged, and is more often than not, quite a simple fix.
Repairing a Leaking Radiator Spindle
Use a spanner to tighten the gland nut and check to see if the leak stops.
If this doesn't work, undo the gland nut and wrap PTFE tape down into the spindle.
Retighten the gland nut and check for leaks.
If this still doesn’t stop the leak, you may have to drain down the system and replace the valve - failing that, it might be time to call a plumber.
Leaking Radiator Gland
The next thing to check if your radiator is still leaking despite having a brand new valve is the gland which sits underneath the plastic lid of the valve. Once again, a potentially easy fix to carry out.
Repairing a Leaking Radiator Gland
Turn off the valve and check to see if any water is leaking from under the plastic cap.
If it does, proceed to also turn off the lockshield valve.
Take off the plastic cap and carefully unscrew the gland nut with your adjustable spanner.
Wrap PTFE tape around the valve spindle and push some of it down into the body of the valve using a flat-head screwdriver.
Scew the gland nut back on tightly and replace the plastic cap. Turn the valve back on and check for any further leaking.
Leaking Radiator Pipe Joint
Compression valves are usually used to join radiators to their respective pipework in modern central heating systems. Should any of these compression joins spring a leak, it is possible to perform a quick fix by retightening the valve with a spanner.
Repairing a Leaking Pipe Joint
However, if this doesn’t solve the problem and the leak persists, you can try the following:
Drain down the system to below the source of the leak.
Take a spanner, undo the nut at the joint of the leaking pipe, and pull the pipe free.
Where the face of the olive meets the joint, wrap around a couple of turns of PTFE tape and then re-tighten the nut.
Discovering a leak in your radiator can be frustrating, but it's likely easier to fix than you think. If however, you do need to replace your radiator or valve, we offer a wide range of radiators, from the ever-popular Column Radiators and standout flat fronted models to modern heated towel rails. Additionally, we stock a wide range of radiator valves & accessories to keep your radiator running smoothly.
