In the second part of this series aimed to help you increase the energy efficiency of your home, we’re showing you how to check your radiators are working as efficiently as possible.


1. Bleeding radiators

If your radiators are not hot from top to bottom this is usually a sign that there is trapped air inside the radiator which prevents efficient circulation and heating. This will typically mean your home will take longer to get warmer, use more energy and increase costs.

Bleeding your radiator is the process of letting out any air in the system and is quite easy to do.

  1. Check your manufacturers guidelines for any specific guidance for your radiators. If you are not sure what to do we recommend you contact a professional.

  2. Make sure your heating system is turned off and that your radiators are cold to the touch.

  3. On the bleed screw, position the outlet so you can see it, preferably facing down. Have a cup ready to catch any water.

  4. Slowly loosen the bleed screw. Do not completely remove the bleed screw. If you have trapped air, you should hear a hissing sound as it escapes. As soon as water starts coming out you have removed all air and can tighten the bleed screw back up.

Radiator Bleed Image

Picture: once water starts coming out of the outlet, you have removed all excess air from your radiator and can tighten the bleed screw.

If you are unsure or you still experience problems, we recommend you consult a GasSafe heating engineer to do an in-depth assessment. It is possible that you may need to flush your system to remove sludge or limescale that can build up over time.


2. Getting the most out of your radiators

Radiators work by heating up the air. As this happens the hot air rises sucking in cold air from below. If you want to get the most heating from radiators try to avoid tucking curtains behind your radiators or placing sofas or other furniture in front of them to allow for better space to heat your room.

Sofa blocking air flow of radiator


3. Radiator reflective panels

Reflective panels help to bounce the heat away from the wall and back into your room, but their significance in helping reduce energy consumption and costs is marginal. They can be helpful in uninsulated solid wall properties on walls that are exposed to the outside. If your walls are insulated or a party wall connected to a neighbour it is not as useful. Hacks using tin foil instead of reflective panels are even less impactful as it loses its reflective capability quickly through oxidation.


4. Cleaning your heating system?

Your radiators and the water that flows through them can corrode over time. During installation a Central Heating Inhibitor is usually added to help prevent the build-up of sludge.

However, it is recommended to flush your system every 5 years to keep it running smoothly. This will benefit both your boiler and radiators, so it is worth considering for longevity. Most boiler warranties require a service once a year to remain valid and your heating engineer can help you assess if it’s required, ideally done before the winter kicks in.


5. Which radiators to use 

Being able to control how hot each radiator gets could help you reduce you carbon footprint and monthly bill. 

Most modern radiators have Thermostatic Radiator Valves (TRVs) to control the flow of hot water to your radiator. This allows the heat produced by the boiler to be focused towards your preferred rooms to warm them quickly and by using less energy, especially if you are unlikely to be using all the rooms in your home equally at any given time.  

We don’t recommend you turn your radiator valves all the way down to zero as during colder months you want a small amount of heat to keep circulating to avoid pipes freezing. It’s also beneficial to keep your radiator turned up in bathrooms to help reduce condensation and mould from building up. 

If you don’t have TRVs then perhaps now is a good time to get some. Prices range from about £15 for simple valves (not including installation), but you can also get smart radiator valves, like this one from tado°, which allow you to control the radiator from your phone, and pair it with your smart thermostat for maximum control. 

Tado TRVs


6. Changing your radiators

When changing your radiators, it is important to check the heating output required for your property to select the right sizes to comfortably heat a room. Too small, and it may not be capable of getting the room temperature you would like and require you to keep the heating on for longer periods of time.

It's recommended that you stick to the same type of metal as those already in your system as multiple types of metals can lead to more corrosion and that will hurt your heating system efficiency and potentially your boiler.