How do I turn my radiator(s) off? Dan Bayliss March 21, 2023

How do I turn my radiator(s) off?

Radiator being turned off by thermostatic radiator valve

In this blog we’ll look at how you can turn your radiator or radiators down or off. We will look at how this is done for radiators with manual valves, thermostatic radiator valves and lockshield valves.

We’ve covered how to balance your radiators and how to fix a cold radiator in other blogs, so if that’s more what you’re after, then head on over.

Why would I want to turn my radiator off?

There are several reasons why:

  1. Energy savings: If you are not using a room, turning off the radiator can save energy and reduce your heating bills. The Cost of Living Crisis has made all of us pay more attention to how much we spend on central heating.
  2. Comfort: If a room is already warm enough, turning off the radiator can prevent overheating and create a more comfortable environment.
  3. Maintenance: If you need to perform maintenance on the radiator or the heating system, turning off the radiator is a necessary step to ensure safety.
  4. Ventilation: If you want to ventilate a room by opening windows or doors, turning off the radiator can help to prevent heat loss and save energy.

It’s important to note that reducing heat from radiators can affect the temperature in the rest of the house, as the heating system is interconnected. If you have a programmable thermostat, you can set it to lower the temperature in the room when the radiator is turned off to ensure that the rest of the house stays warm.

Turning the temperature down on rooms you use less frequently will also help you save money on those ever-increasing energy bills. It’s natural for some rooms to get hotter than others (bigger windows, facing the sun) so you may want to turn the temperature down in these rooms also.

What’s the difference between isolating a radiator and turning It off?

Isolating a radiator means turning off the flow of hot water to it, leaving the flow of hot water to other radiators in the system. This is typically done using valves on the pipes leading to and from the radiator.

Turning off a radiator, on the other hand, means completely shutting off the flow of hot water it. This is done by closing both the valves on the pipes leading to and from the radiator.

So, the main difference is that isolating a radiator allows you to control the heat flow to each one while turning off a radiator completely cuts off the heat flow to that specific one. 

Why would I want to isolate a radiator?

There could be several reasons for isolating a radiator, such as:

  1. Repair or maintenance: If a radiator needs to be repaired or replaced, isolating it from the rest of the system will allow you to do so without affecting the others within the system.
  2. Energy efficiency: If you have a room that is rarely used, you can isolate the radiator in that room to save energy and reduce your heating bills.
  3. Zoning: Isolating radiators allow you to create different heating zones in your home. For example, you may want to isolate the ones in bedrooms during the day when no one is sleeping or isolate the ones in a home office during the evening when the rest of the house is being heated.

Overall, isolating radiators gives you greater control over your heating system, which can help you save energy, reduce heating bills, and make your home more comfortable.

Cut out image of radiator

Knowing what type of radiator valve your radiator has

Although it may not be particularly interesting, it is particularly useful to know the difference between the 3 main valve types on a radiator.

Manual valve
This is the old-fashioned type that you can use to turn your radiator on and off. It’s also called a wheelhead or control valve. It’s only got two positions – on or off – so that’s the only control you have over the amount of hot water flowing into it.

Thermostatic Valve (TRVs)
Most modern radiators have a thermostatic valve instead of a manual valve. TRV’s are highly recommended to give you more control over your heating by allowing you to turn the temperature dial up or down with ease.

A smart thermostatic valve is an upgrade of a standard TRV. Unlike traditional valves that only let users turn radiators on and off, smart thermostatic valves allow users to control the temperature of the radiators independently, depending on individual needs in each room.

They can be connected to smart home devices and controlled using your phone or tablet, making it easy to adjust temperature settings whenever needed.

Some models also have additional features such as sensors that can detect when someone enters or leaves a room, helping to save energy and reduce costs by automatically adjusting the heating settings accordingly.

As the name implies, TRVs have their own thermostat so that once the surrounding temperature reaches your desired level, the valve regulates the hot water flow into the radiator and only uses as much energy as needed. Keep TRVs away from your general room/house thermostat – if they’re in the same room they will interfere and compete with each other.

Lockshield valve
This is the one covered by a small domed plastic cap and it looks like you can’t really do much with it. In fact, you need to use grips of some kind to pull off the plastic cap. Some have a screw through the top of the cap that must be removed before the plastic bit can be pulled off. Underneath the cap it looks like the end of a flat-head screwdriver.

Smart TRV

These types of TRVs are helping to bring technology to help operate the heating of your home. A smart TRV is operated via a smart device and can monitor a single radiator’s energy usage and temperature as well as remotely alter the radiator’s temperature. These are ideas for when you may unexpectedly need to turn off or lower your radiator’s temperature, even if you are away from home. Smart TRVs can be accessed anywhere at any time if you have an internet connection.

How do you turn off a radiator with a thermostatic radiator valve (TRV)?

Follow these steps:

  1. Locate the thermostatic valve. It is usually located on the side of the radiator and has numbers or symbols indicating temperature settings. Smart TRVs may have a digital display but the way to turn them off is the same as that of a standard TRV.
  2. Turn the valve to the lowest temperature, usually marked with a snowflake symbol or a 0. This will prevent the radiator from heating up.
  3. Alternatively, some thermostatic valves have an “off” position, which you can turn the valve to stop the flow of water entirely, and turn the knob or handle until it clicks or reaches the off position.
  4. To turn the radiator back on, simply turn the valve to a higher temperature setting, usually marked with numbers or a symbol.

Note that in some cases, thermostatic valves may be stuck. If you cannot turn off your radiator using the TRV, you may need to seek professional help from a heating engineer or plumber to repair or replace the valve.

Tado TRV and Receiver

How do you turn off a radiator with a manual valve?

Follow these steps:

  1. Find the manual valve located on the pipework leading to the radiator. It should be near the bottom of it and may have a handle or knob attached to it.
  2. Turn the valve handle clockwise to close the valve, when you’ve moved it clockwise as far as it will go, give it a little quarter turn back to the other way. This is to stop water inside your radiator from potentially freezing. You don’t need to worry about this with TRVs as they have in-built frost protection.
  3. If you need to turn the radiator back on, turn the valve handle counterclockwise to open and allow hot water to flow into it again.

Note that manual valves can sometimes become stiff or stuck over time. If you have issues using the valve, you may want to apply a bit of gentle force.

If in doubt always seek professional help, don’t force a valve too much, and end up with black water spraying everywhere, we’ve been there, and it isn’t pleasant!

How do I replace manual valves for TRVs?

Replacing a manual valve with a thermostatic radiator valve (TRV) involves plumbing work and should be done by a qualified professional if you are not experienced or comfortable you know what you’re doing. If you are comfortable, here is a general guide to the process:

  1. Shut off the central heating and close the valves on both sides of the radiator. Allow the radiator to cool down completely.

  2. Use a spanner to detach the old manual valve from the pipework on the radiator. Be sure to have a container ready for any water that leaks from the pipes as you remove the valve.

  3. Use some PTFE tape to wrap the threads of the new TRV valve to ensure it’s watertight when it goes on. Attach the new TRV valve to the radiator, tightening it until it is secure.

  4. Connect the thermostatic head to the valve body.

  5. Finally, turn the water supply back on and check for any leaks around the valve. Once the valve is installed, turn the central heating back on and check to make sure the temperature is regulated properly.

It is important to remember that TRVs can be more expensive than manual valves, so it’s best to do research and shop around before making a purchase. They also offer more features, smart TRV’s in particular, so find out what they offer first before committing.

You can purchase smart home TRVs or regular TRVs with WarmZilla, with installation included (when ordering 5 or more TRVs). Installation costs £175 and TRV prices range from £7.99 per TRV to £79.99 per smart TRV.


You may want to turn your radiators off to save money on your energy bills by not heating rooms you aren’t using. Certain rooms can naturally be hotter than others, so you may not need to heat them as much (or at all).

If you need to perform maintenance on your heating system or you’re redecorating, you may want to turn a radiator off.

Isolating a radiator allows you to control the heat flow to each radiator, while turning off a radiator completely cuts off the heat flow to that specific radiator.

There are three main types of radiator valve. Lockshield valves, manual valves and thermostatic radiators valves.

Lockshield valves are the ones with the white plastic caps on them and a metal spindle underneath to control water flow.

A manual valve is a plastic cap that you can turn clockwise or anti-clockwise to turn the radiator water flow off and on.

A thermostatic radiator valve is similar to a manual valve, but it has a temperature dial, allowing you to control the water flow to the radiator and adjust the temperature.