The most efficient way to use radiators. WarmZilla Blogs.

Since the record-high energy price hike in August 2022 of £363.70 a megawatt-hour, UK residents have proactively been working to reduce their monthly bills. While there have been marginal improvements in cost-of-living inflation rates, down 4.7% in October 2023, most citizens are still recovering financially.

Many are looking for ways to reduce their energy bill to assist with this financial recovery. One standard heating solution many British citizens share is radiators. In 2019, boiler systems with radiators were the most common heating system, with 22.1 million (90%) dwellings using one.

Boiler radiator systems are also the most significant energy user in UK households. With most Britains owning multiple radiators, you need to know how to run a radiator efficiently if you're looking to reduce your energy bill.

But how does a radiator work?

How do Radiators Work?

Hot water radiators are the most common type used in UK homes. Radiators work on the principle of convection and radiation.

In boiler radiator systems, the boiler is used to heat water fed into the property from the council mains. While multiple sources can heat boilers, most central heating systems (86%) in the UK still run off gas.

The heated water is circulated through the home’s network of piping, which makes up the bulk of the heating system.

Hot water enters the radiator via an inlet valve from this network. Usually, these radiators will be fixed against a wall in rooms that require additional heat.

As the hot water flows through the radiator, it gives off heat to the surrounding area, which rises. As this happens, the radiator draws cooler air in from the rest of the room, creating a natural circulation of air.

Via radiation, the hot radiator also transmits infrared heat. This is a form of electromagnetic radiation that travels through the air and is absorbed by objects and surfaces around the room.

When the water cools off inside the radiator, it sinks. The temperature of your radiator is maintained through the use of valves. There are many types of valves, including lockshield, manual, thermostatic radiator valves (TRV), and smart valves.

Currently, the most common inlet valves in the UK are TRVs. Connected to the radiator's top or side, they can maintain a constant temperature. These valves work by being temperature-sensitive, expanding, and contracting to maintain heat levels.

Now that we understand how radiators work, how does your boiler impact your radiators’ performance?

How Does My Boiler Impact My Radiators?

As boiler specialists, we can attest to the importance of choosing the correct boiler for your radiators. Your boiler’s performance will determine the efficiency and effectiveness of your radiators.

Here’s how your home’s boiler affects your radiator:

Heat Production

As you’d expect, your boiler’s primary function is to produce heat. Depending on what boiler you’ve installed, it will use a fuel source to generate hot water or steam.

This heated water is then circulated through the pipes connected to your radiators.

Temperature Control

Your boiler’s temperature sets the heat for the entire system. The more efficient it is at converting fuel into heat, the lower your energy bill will be.

Schedule regular maintenance checks to ensure your boiler is operating at its best.

Compatibility With Radiators And Heating Systems

A highly efficient boiler will not operate at its peak if connected to an old system. Older systems also tend to be less well-insulated than newer ones, and most of your heat is lost when piped to the radiators.

Also, when you consider that some boilers will come equipped with advanced features like zoning and control systems, configuring these new settings into older networks will be impossible, and you’ll lose energy savings.

But to ensure your radiators are working most efficiently, you must maintain and balance them.

How To Balance Your Radiators To Maximise Efficiency

Balancing your system and radiators is when you ensure an even distribution of hot water throughout the heating system. When done correctly, it will help maximise your heating system’s efficiency.

You need to perform a few steps to ensure your system is balanced. These include:

Turn Off The System

Before working on your heating system, ensure it is off. And allow for the radiators to cool down.

Know Your Valves

As we discussed, there are three types of valves. Make sure to open the valves. Usually, TRVs are fitted to radiators on their inlet pipe, while lockshield valves will be attached to the outlet.

Once you’ve opened all your valves, it is time to switch on the system.

Check How Your System Heats Up

All your radiators should be open and receive hot water. Run the system to heat each radiator. This will happen in a series, with the closest radiator warming up first.

Note the order in which your system distributes its hot water.

If you live in a home with multiple rooms, ask for help checking the order in which the radiators warm up. Once you are sure of the order, switch off the heating system.

You must allow the system to cool down entirely because the next step is minor adjustments. Making these small adjustments from a cold start is best.

Now, it's time to start from the beginning.

Start From The Beginning

To begin, turn the heat back on and go to the first radiator.

Make sure to close the lockshield valve and then gradually open it again. By adjusting the flow out of the radiator, you will be setting the temperature.

Once it is warm, it’s time for temperature adjustments.

Taking Temperatures

When you’re happy with the temperature, take a reading on the pipework leading to the inlet valve.

Compare its reading to the outlet valve; it will most likely be on the other side of the radiator.

Now, take a reading of the temperature at the lockshield valve and adjust it until it is 12°C lower than the inlet.

After you’ve achieved this step, it's time to repeat the process. You will notice that the lockshield valves will start to be opened more the further away from the boiler they are situated in the home, and this is normal.

Once this is completed, you’ve successfully balanced your system!

But what if your radiators still have cold spots towards the top and make a noise? You will have to bleed your radiator. It’s a common misconception that balancing and bleeding a radiator are the same process.

How To Bleed UK Radiators

Bleeding a radiator is a simple task that involves releasing air from the system. Air can accumulate over time and make your radiator less efficient.

All you need to bleed your radiator is a radiator key or flat-head screwdriver and a towel.

Before you turn off your heating system, let it cool down. Now, when you’re at the radiator with the issues, locate the bleed valve. This will usually be found on top of the radiator.

It will look like a small square-shaped valve with a central spindle. Once you’re happy that you know where all the elements are, prep the area just in case water spills out onto the floor.

Open the bleed valve by turning it anti-clockwise using the radiator key or screwdriver. You should hear a hissing noise of air escaping the system. Make sure to have a small container and a cloth on hand to catch the water spilling out.

Keep the valve open until there’s a steady stream of water from the radiator, and then close it. Be careful to avoid overtightening, as this can cause issues further down the line.

Now that you’ve bled the system, you will need to check if the pressure in the system is correct.

When you’re happy that the system is repressurised, you can bleed another problem radiator or turn the system back on if you’re complete with the task.