Heating controls

A timer or programmer controls when your heating comes on and off.

If you have a hot water cylinder, you will also have a timer to control when your water is heated, too.

This is useful because you can programme your heating to fit your routine. If you’re not at home or don’t need heating at night, you can programme the heating to switch off during these times.

If you have a hot water cylinder, you’ll also have a timer to control when your water is heated, too.

Older programmers are simple timers that only run once a day, but modern programmers offer options to control multiple on and off periods.

Depending on how your central heating system was installed, programmers are either:

• Single channel: for combi boilers. This only controls central heating as hot water is provided on demand.
• Two channel: for system boilers controlling heating and hot water, or combi boilers controlling two heating zones (eg upstairs and downstairs).
• Three channel: for system or regular boilers controlling hot water and two separate heating zones (eg upstairs and downstairs).

A room thermostat keeps your home at a steady temperature. It turns the heating on until it reaches your chosen temperature, then switches it off until the room cools slightly.

You should set your thermostat to the lowest comfortable temperature, which for most people is between 18°C and 21°C. And if you turn the thermostat down by just one degree, from 22°C to 21°C, you could save £120 in GB and £80 in NI.

You don’t need to turn your thermostat up when it is colder outside. The house will heat up to the set temperature regardless. It may take a little longer on colder days, so you might want to set your heating to come on earlier in the winter.

A programmable room thermostat combines a timer and thermostat in a single control. If you’re not sure whether you have one, look for a control that lets you set both heating schedules and target temperatures.

You can programme different temperatures for different times of the day to match your routine. For example:

• In the morning, when you’re up and moving around, you might be comfortable with the heating set to 18°C or lower.
• In the evening, when you’re relaxing at home, you might prefer a warmer temperature of 20°C or 21°C.

The thermostat monitors the temperature in your home and turns the heating on and off as needed to maintain your chosen temperature. This helps keep your home comfortable while avoiding unnecessary energy use.

Some homes have more than one programmable room thermostat. For example, you may have separate controls for upstairs and downstairs, allowing different parts of the home to be heated to different temperatures.

Many programmable room thermostats also include a setback temperature. This is the minimum temperature you don’t want your home to fall below when you’re out or asleep.

For example: you might set your home to 20°C when you’re at home and awake. But overnight or while you’re out, you might allow it to cool to around 12°C to 15°C. This can help reduce energy use while preventing your home from becoming excessively cold.

You may need to maintain a higher minimum temperature if someone in your household:

• is older
• has a health condition that makes them more vulnerable to the cold
• spends long periods at home.

Comfort and health should take priority over energy savings.

During very cold weather, you may find that your home takes longer to warm up. Consider bringing your heating on a little earlier rather than increasing the thermostat setting. Turning the thermostat up higher won’t heat your home any faster.

Thermostatic radiator valves (TRVs) help you control the temperature in individual rooms. To save energy, set each TRV to the lowest setting that keeps the room comfortable. For example, you might keep a spare bedroom cooler than your living room.

TRVs work by controlling how much hot water flows through the radiator they’re attached to. The valve senses the temperature of the air around it and automatically adjusts the flow of hot water. As the room warms up, the valve reduces the flow. When the room cools down, it allows more hot water through.

Most TRVs have a numbered dial. The numbers don’t correspond to the same temperature on every model. But, in general, lower numbers mean a cooler room and higher numbers mean a warmer room.

If you’re not sure where to start, try setting the TRV to a middle setting. If the room feels too warm, turn it down. If it feels too cool, turn it up. The aim is to find the lowest setting that keeps the room comfortable.

If a room is used less often, you may want to keep it at a lower temperature than the rest of your home. However, it’s usually best not to leave rooms completely unheated for long periods, especially during colder weather. Keeping some background heat can help reduce the risk of condensation and mould.  It’ll also make it easier to warm the room when you do want to use it.

We generally don’t recommend using radiator covers. They can stop the TRV from sensing the room temperature accurately by trapping warm air around the valve. This can cause the radiator to switch off sooner than needed, leaving the room cooler than intended.

These are TRVs with timing control as well. They let you set each radiator to come on at different times and heat each room only when you want to. Some models can be connected via Wi-Fi to smart heating controls, letting you create a new zone for each room.

Smart heating controls can do everything that conventional controls do. The main difference is that smart controls are connected to the internet and offer more functionality.

Some of the features they can offer include:

• Easy to use time and temperature controls with user friendly interfaces. These make it easier to check and change the on/off periods for heating and hot water.
• Letting you turn the system on or off and change the temperature using your smartphone when you’re not at home.
• Learning your habits and adjusting controls to match or, for example, turning up the thermostat in the evening.
• Tracking where you are by using your smartphone’s location. This feature is known as ‘geo-fencing’. It can automatically turn off your heating when you’re away and switch it back on before you return home. You can set this automatically, or it can send a notification to your smartphone asking for your permission before it makes any changes.

Many of these features are optional and you change the settings to suit your preferences. For example: you could choose to not to use the option where it tracks your location.

Whether smart heating controls will save you money will depend on how you currently control your heating. For more information, read out expert blog on smart energy saving tech

The thermostat stops the cylinder becoming hotter than it needs to be. Once the water reaches the set temperature, the heat supply from the boiler will be turned off.

You should set the temperature of the hot water thermostat to 60°C. This is hot enough to kill harmful bacteria in the water, but be careful, as it’s also hot enough to scald.

Your boiler’s thermostat controls how hot the water gets before it’s pumped to your radiators. This is called the flow temperature. As this water travels through your radiators, it cools down before returning to the boiler at what’s called the return temperature.

If your flow temperature is set higher than needed, lowering it could save you money. This is because a lower flow temperature means a lower return temperature, which helps your boiler work more efficiently.

However, be careful not to set it too low. If the flow temperature isn’t high enough, your radiators won’t get hot enough to warm your home properly, especially during cold weather. You’ll need to find the right balance between efficiency and keeping your home warm enough.

If you have a regular or system boiler with a separate hot water cylinder, there’s only one control for both your radiators and hot water. You need to make sure the temperature is set high enough so that you have hot water. This should be no lower than 65°C so that it can heat your cylinder to 60°C. This is very important to prevent the growth of harmful bacteria.

For more information, read our blog on how to turn down your boiler flow temperature.

A weather compensator automatically measures the outside temperature and adjusts the boiler thermostat temperature as needed. This means you don’t have to worry about keeping your boiler running efficiently as the weather becomes colder or warmer.

A load compensator measures the difference between the internal air temperature and what has been set on your room thermostat. It can then adjust the boiler thermostat to prevent overheating.

If you have a system or regular boiler with hot water cylinder, you should have a programmer, room thermostat and cylinder thermostat. These controls should be connected to create a ‘boiler interlock’. This means the boiler switches off if the heating and hot water thermostats have reached their set temperatures.

Without an interlock, the boiler keeps running even if the heat isn’t needed.  Most modern heating systems are fitted with boiler interlock controls as part of current building standards. These controls switch the boiler off when there is no demand for heating or hot water, helping to improve efficiency and reduce energy use.

If you want to heat different rooms at different times of the day, zone controls do this for you automatically.

They do this by having separate programmable heating circuits for different parts of the house. This usually includes one zone upstairs and another downstairs, but you could have more zones. For example, homes with underfloor heating sometimes have a room thermostat for each room, meaning each room is a zone.

If you’re fitting a new heating system, consider zone controls to help keep your heating costs down by avoiding heating rooms you’re not using. You might need zone controls to meet building regulations if your home is large enough.

If you’re not fitting a new system, using programmable TRVs may be a more practical solution.