Which Way to Turn Radiator On?

Which Way to Turn Radiator On?

Turning on a radiator can sometimes be confusing, especially if you’re not familiar with the heating system in your home. Understanding which way to turn radiator on is essential for ensuring that your home stays warm and cozy during the colder months. In this guide, we’ll walk you through the process of turning on your radiator and provide some tips on how to manage your heating system efficiently.

Understanding Your Radiator

Before diving into which way to turn radiator on, it’s important to understand the basic components of your radiator. Most radiators have a valve on either end: a manual control valve and a thermostatic radiator valve (TRV). The manual valve controls the flow of hot water into the radiator, while the TRV adjusts the temperature.

Manual Control Valve

The manual control valve is typically located at the bottom of the radiator. To turn this valve on, you generally need to rotate it counterclockwise. This action allows hot water to flow into the radiator, which in turn heats up the room. If you’re unsure which way to turn radiator valve, remember that counterclockwise usually opens the valve, while clockwise closes it.

Thermostatic Radiator Valve (TRV)

The TRV is designed to regulate the temperature of the radiator. It usually has numbers or settings on it, which correspond to different temperature levels. Turning the TRV to a higher number increases the temperature, while turning it to a lower number decreases it. Knowing which way to turn radiator valve for temperature control can help you maintain a comfortable environment without wasting energy.

Steps to Turn On Your Radiator

Now that you have a basic understanding of the components, let’s go through the steps to turn on your radiator.

  1. Locate the Valves: Find the manual control valve and the TRV on your radiator. The manual valve is usually at the bottom corner, while the TRV is at the top or on the side.
  2. Check the Manual Valve: If the radiator is off, the manual valve will likely be in the closed position. Turn the valve counterclockwise to open it. This will open the flow of hot water into the radiator
  3. Adjust the TRV: Set the TRV to your desired temperature. If you want the room to be warmer, turn the TRV to a higher number. For a cooler room, turn it to a lower number.
  4. Bleed the Radiator: Sometimes, air can get trapped inside the radiator, preventing it from heating up properly. To bleed the radiator, use a radiator key to open the bleed valve slightly until you hear a hissing sound. Once the water begins to flow, shut off the valve. This ensures that the radiator is filled with water and can heat up efficiently.
  5. Monitor the Temperature: After turning on the radiator, monitor the room temperature. Make sure the TRV is adjusted appropriately if the room is too hot or cold.

Troubleshooting Common Issues

Even if you know which way to turn radiator on, you might encounter some common issues. Here are a few troubleshooting tips:

Radiator Not Heating Up

If your radiator isn’t heating up after you’ve turned it on, check the following:

  • Manual Valve: Ensure that the manual valve is fully open. Turn it counterclockwise until it stops.
  • TRV: Check the TRV setting. It should be set to a number high enough to allow heating.
  • Bleeding: Make sure the radiator has been bled properly to remove any trapped air.

Uneven Heating

If parts of the radiator are warm while others are cold, it might be due to trapped air. Bleed the radiator again to ensure even heating. If the problem persists, you might need to balance the radiators in your home by adjusting the lockshield valve (usually located opposite the manual valve).

Noisy Radiator

A noisy radiator can be annoying. A leaky valve or trapped air are the usual causes of this noise. Bleed the radiator to remove any air, and tighten the valves if necessary. If the noise continues, there might be an issue with the boiler or the central heating system, and you may need to call a professional.

Energy Efficiency Tips

Knowing which way to turn radiator on and which way to turn radiator valve can help you save energy and reduce heating costs. Here are some tips:

  • Set the TRV to a Lower Temperature in Unused Rooms: Don’t waste energy heating rooms that are not in use. Set the TRV to a lower temperature or turn off the radiator completely in these rooms.
  • Use a Programmable Thermostat: A programmable thermostat can help you control the heating schedule in your home, ensuring that radiators are only on when needed.
  • Regular Maintenance: Keep your radiators and boiler well-maintained to ensure they operate efficiently. This includes bleeding radiators regularly and servicing the boiler annually.
  • Insulate Your Home: Proper insulation reduces heat loss, making your heating system more efficient.


Understanding which way to turn radiator on and which way to turn radiator valve is crucial for maintaining a comfortable and energy-efficient home. By following the steps outlined in this guide, you can ensure that your radiators are functioning properly and that your home stays warm during the colder months. Regular maintenance and mindful use of your heating system will not only improve comfort but also help you save on energy bills.

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