How To Turn Off A Radiator When It Leaks

Whether your home has steam radiators, hot water radiators, or hydronic or convector baseboard heaters, those radiators typically operate by heating water or steam and then circulating it through a system of pipes. As with any home appliance that involves water, inevitably you will face the problem of a leak.

Water will leak from a radiator for any number of reasons. If the pipes or joints are older, corrosion may result in water dripping out. If the leak is at the radiator’s valve, it usually means that the packing or a washer inside the valve is worn out and so the valve needs to be replaced. If you are unable to identify the location of the leak, dry the exterior of the radiator and brush some dish soap in places. The soap will bubble slightly when it comes into contact with the leak.

If you spot water leaking from your radiator, it is important that you act quickly to turn off the radiator and stop the flow of water. As with any water coming out of an appliance, a leaking radiator can cause additional damage. Because water in a radiator has been in contact with corroding and rusting metal, it will stain wood, fabrics, and other surfaces. A leak can also be a symptom of a more dangerous underlying problem.

How you should turn off the radiator depends on the type of radiator and leak you have.

Steps to Turn off the Radiator Properly

1. If your radiator is connected to the house’s power supply, first disconnect power to it. This is especially important if water is present on or around the radiator. You should also find your heating system’s power switch and turn it off; allow the system to cool completely before attempting any repairs.

2. If the leak is coming from the valve, you may be able to temporarily stop it by turning the valve fully to the opened or to the closed positions. Even if this stops the leak, however, it will not solve the problem in the long-run and the valve will need to be replaced.

3. If you have water-based baseboard heaters, find the air bleeder valve—a small metal nipple on the end of the unit. Tighten this with a flathead screwdriver to make sure it is not leaking.

4. If your radiator has a thermostatic valve on the left, it may have an off setting. Turn the dial to “off”—or “0” on some models. Once the thermostatic valve is off, turn the valve on the right of the radiator clockwise until it stops. This closes the radiator and will allow it to cool down.

5. If your radiator has a lockshield cap on the right side valve, remove the screw and then lift the cap off. Use a pair of pliers to turn the valve underneath the shield clockwise until it stops. Do not touch the valve with your hands as it may be hot.

While some damage to a radiator can be repaired with simple tools, other leaks will require professional service. If a leak is coming from a pipe, it must be drained and repaired by a professional plumber. It is important not to attempt to alter the home’s boiler or central heating system in an effort to stop a radiator from leaking.