Knowing how to turn off your cast iron radiator is essential for energy efficiency, comfort, and maintenance. It allows you to control room temperatures, directing heat where needed and conserving energy in unused spaces. Additionally, being able to turn off radiators is crucial for maintenance tasks like bleeding or painting, ensuring a well-functioning heating system and preserving the longevity of your radiators. And luckily, it’s a quick and simple 4-step process!

4 Steps to Turning Off Your Cast Iron Radiator
With these 4 simple steps, you will be able to turn off your cast iron radiator with no problem, allowing you to better control the temperature of your rooms and safely perform maintenance tasks on your radiator.
- Locate the Radiator Valve
Identify the thermostatic radiator valve (TRV) or manual valve on the side of the radiator that controls the flow of hot water.
- Adjust the TRV (if applicable)
If you have a TRV, turn it to the “0” or “Off” position. Some TRVs have numbers indicating different temperature settings; set it to the lowest or “Off” setting.
- Use a Lockshield Valve (if applicable)
If your radiator has a lockshield valve, turn the valve clockwise to close it. This valve is usually located on the opposite side of the TRV.
- Wait for Cooling
Allow the radiator to cool down. This may take some time, especially if the heating system was on. Gently check the radiator after a while to ensure has cooled completely.



