How to Turn On Radiator Heat

Radiators are still one of the most common and reliable ways of heating homes across the UK. Whether you live in a new build, a Victorian terrace or a converted flat, chances are your property relies on radiators connected to a central heating system. While they are straightforward to use once you know the basics, many people are unsure about how to turn on radiator heat properly, particularly when moving into a new property or dealing with older systems. Understanding how your system works will not only help you keep your home comfortable but also ensure that it runs efficiently and safely.

Understanding Your Central Heating System

Most UK homes with radiators use a central heating system powered by either a gas boiler, an oil boiler or in some cases, an electric boiler. The boiler heats water which is then pumped through pipes into each radiator. The radiators transfer heat from the hot water into the air, warming your home.

Before trying to turn on the radiators, it is useful to know whether your boiler is a combi system, which provides both heating and hot water on demand, or a system boiler with a hot water cylinder. This matters because the way you control the heating may be slightly different.

Using the Boiler Controls

The first step in turning on radiator heat is to check your boiler controls. Most boilers will have a main power switch or dial that allows you to switch between off, hot water only, heating only or both heating and hot water. To heat your radiators, you will need to select either heating only or both.

If your system has a digital programmer or smart controller, you may need to set the heating to manual or programmed mode. A manual setting allows you to switch the heating on and off yourself, while a programmed setting means the system will automatically turn the radiators on at the times you have chosen.

Adjusting the Thermostat

Once the boiler is set to heating mode, the next step is to check your thermostat. This is usually located in a hallway or living space and controls the overall temperature of the home. If the thermostat is set too low, the boiler will not fire up and your radiators will remain cold. Turning the thermostat up a few degrees above the current room temperature should trigger the heating to come on.

Modern smart thermostats can be controlled via an app, which means you can adjust your heating remotely. Traditional thermostats will have a simple dial or digital display.

Checking the Radiator Valves

Each radiator has valves at the bottom which control the flow of hot water. The main types are manual valves and thermostatic radiator valves (TRVs). Manual valves act like a tap, which you open or close to control the heat. TRVs have numbered dials, usually from one to five, which allow you to control the temperature in each room individually.

To turn on radiator heat, make sure the valves are open. On a manual valve, this means turning it anticlockwise. On a TRV, this means rotating the dial to the desired number. If a radiator valve is fully closed, no hot water will flow into the radiator, and it will stay cold even if the heating is on.

Bleeding the Radiators if Needed

Sometimes, radiators fail to heat up properly even when the heating is switched on. This is often due to air trapped inside. Air prevents hot water from circulating fully, leaving radiators cold at the top but warm at the bottom.

If this happens, you may need to bleed the radiator. This involves using a radiator key to open the small bleed valve at the top until air escapes, followed by a trickle of water. Once the air has been released, close the valve and the radiator should heat up more effectively. It is advisable to have an old cloth or small container ready to catch any drips.

Balancing the System for Even Heat

In some homes, radiators closer to the boiler heat up quickly, while those further away stay lukewarm. This is a sign that the system may need balancing. Balancing involves adjusting the lockshield valve, usually found at the opposite end of the radiator to the control valve, to ensure hot water is distributed evenly. While homeowners can attempt this, many prefer to ask a heating engineer to carry out balancing for consistent heat throughout the property.

Energy Efficiency and Best Practice

When turning on radiator heat, it is worth considering efficiency. Running the heating at a lower but steady temperature often saves energy compared to turning it on and off frequently. Using TRVs to control temperatures in less-used rooms can also save money. Insulating your home and ensuring radiators are not blocked by furniture will help make the most of the heat they provide.

When to Call a Professional

If you have followed all these steps and your radiators are still not working, it may be time to call a professional heating engineer. Common problems include faulty thermostats, broken valves, circulation pump issues or problems with the boiler itself. Annual servicing of your boiler and system is recommended to keep everything in good working order.

Conclusion

Learning how to turn on radiator heat is a straightforward process once you understand the basics of your heating system. By checking the boiler, adjusting the thermostat, opening radiator valves and maintaining your system properly, you can keep your home warm and efficient throughout the colder months. For more complex issues, a qualified heating engineer should always be consulted to ensure safe and effective operation.