Should You Leave Your Boiler On All Day?
Not everyone is sure how they should be using their boiler, and a question often asked is ‘should I leave my boiler on continuously?’. This article intends to address that question and clear up some misunderstandings to do with boilers.
Some people believe it is cheaper to leave the heating on low all day. Others prefer to only switch the heating on when they need it. The answer depends on your home, your insulation, your heating controls and how you use each room.
But there is one important distinction to make first. Leaving your boiler switched on is not the same as leaving your heating continuously running all day.
Your boiler can usually remain powered on in standby without using much energy. It is only when the boiler fires up to heat your home or hot water that it starts using a meaningful amount of energy.
So, the real question is not usually whether your boiler should be switched on. The better question is: Should your heating be running all day?
What Is A Boiler?
A boiler is a device used for heating water in order to provide hot water for domestic use. These days, boilers are also often used to heat water for commercial purposes as well.
Currently, there are two main types of boilers: gas-fired boilers and electric boilers. Gas-fired boilers are more common than electric ones, but both work in much the same way.
Gas boilers have an internal combustion chamber burning fuel to heat water. The heat is transferred to the water through a heat exchanger. Electric boilers use electricity to heat water. They do not require fuel combustion and are often used in areas where gas is not available.
Both types of boilers can either be installed into existing plumbing systems or as part of new installations.
Boiler On Standby vs Heating On All Day
In most homes and for the vast majority of people, there is no need to turn the boiler off at the mains every day.
Boilers are designed to stay powered so they can respond when your heating or hot water is needed. This also allows timers, thermostats, smart controls and frost protection settings to work properly.
However, having your heating scheduled to run all day is very different to leaving your boiler powered all day.
If your heating is constantly trying to maintain a set temperature, your boiler may fire throughout the day to replace heat that is being lost through walls, windows, doors, floors and the roof. The more heat your home loses, the harder your heating system has to work.
That is where energy can be wasted.
Is It Cheaper To Leave Heating On Low All Day?
In our experience, in most homes, it is usually more efficient to heat your home to a comfortable level when you need it, rather than keeping the heating running continuously, wasting heat in empty rooms.
If you leave the heating on all day, your system keeps topping up the heat your home is losing. This can be especially wasteful if:
- your home is poorly insulated
- you are out during the day
- you heat rooms you are not using
- you do not have a thermostat
- your heating controls are limited
- your home takes a long time to warm up
For some people, such as elderly or vulnerable occupants, keeping the home at a more consistent temperature may be important for comfort and wellbeing. But for many households, a timed schedule or room-by-room, zoned heating control will usually make more sense.
When Should Your Heating Be On?
Rather than think of your heating as being ‘off’ and ‘on’, it would be better to think in terms of your heating working towards a comfortable temperature or maintaining a low set back temperature (around 15 degrees). The benefits of this are that your heating will be able to respond faster to your comfort temperature request using less effort; your home also will not drop into temperatures than can lead to mould and damp build up which causes health issues.
For most homes, the best approach is to heat the areas you need, when you need them.
A basic timer can help by switching your heating on before you wake up or before you come home. A central thermostat can then help stop your heating from running once your home reaches the set temperature.
However, traditional heating controls with one single thermostat in the hallway for instance, often treat the whole home as one space. That means you may end up heating bedrooms, spare rooms or living areas at times when nobody is using them.
This is where room-by-room heating control can make a real difference.
Energy Saving measures with a boiler:
Helping Your Boiler Work More Efficiently
One of the key ways to help your boiler work more efficiently, is understanding how to help them work at lower effort levels. If the house cools down too much, the boiler has to work extra hard to recover the temperature. Also, the cooler the water temperature is the boiler needs to achieve, the less effort it needs to make. Modern condensing boilers are designed to work most efficiently when they can run at a lower effort, rather than constantly firing at higher temperatures. This is one of the reasons UK Building Regulations moved towards higher-efficiency condensing boilers under Part L, which covers the conservation of fuel and power in buildings. Today, replacement gas boilers will usually need to be condensing boilers unless there is a good reason why one cannot be installed. A condensing boiler performs best when the water returning to the boiler is cool enough for it to recover more heat from the flue gases. These boilers run in condensing mode around the mid 50 degrees range. However, existing homes with radiators tend to use water heated to 60-80 degrees.
This is where lower-temperature heating systems can help. Underfloor heating is well suited to this because it can heat a room effectively using a much larger surface area than radiators, allowing lower flow temperatures (often around 30-45 degrees). Wunda Rapid Response underfloor heating panels are designed to help spread heat quickly and evenly across the floor, helping the room warm comfortably without relying on very high radiator-style temperatures. This can support a more efficient, lower-effort way of heating the home.
Why Heating Empty Rooms Wastes Energy
One of the simplest ways to reduce wasted heat is to avoid heating rooms you are not using.
For example, you may want your bathroom warm in the morning, your kitchen warm at breakfast, your living room warm in the evening and your bedrooms warmed slightly before you go to sleep. But each of those rooms have different ideal temperatures for those functions. For instance, people tend to prefer their living rooms around 21 to 22 degrees, whereas they generally prefer their bedrooms cooler, between 16 and 20 degrees.
A single central thermostat cannot usually manage these different needs properly. It will switch the heating on for the house, even if you only need heat in one or two rooms.
Room-by-room controls allow different areas of your home to follow different schedules and temperatures. This gives you more control over comfort and can help reduce unnecessary heating. This is a topic we go into more depth in this article, especially useful for anyone considering changing to a heat pump in the future
Insulation Still Matters
Heating controls are important, but your home’s insulation also plays a big part in more efficiently using your boiler and helping it to work at a lower effort.
If your home loses heat quickly, your boiler must work harder to maintain the temperature you want. This can make your heating feel less effective and increase your running costs.
Common areas to consider include:
- draughts around doors and windows
- unused rooms being heated unnecessarily
The better your home holds onto heat, the easier it is for your heating system to keep you comfortable.
How Zoned Heating Controls Can Help
Zoned heating controls allow you to heat your home room by room, rather than treating the whole house as one single heating zone.
With a system such as WundaSmart, you can set different temperatures and schedules for different rooms. This means you can heat the rooms you are using and reduce wasted heat in the rooms you are not.
This can be especially useful in homes where different rooms are used at different times of day.
For example, you may want:
- the bathroom warm first thing in the morning
- the kitchen comfortable at breakfast
- the living room warm in the evening
- bedrooms warm before bedtime
- spare rooms kept lower unless they are being used
Instead of heating the whole home all day, zoned controls help you use your heating more precisely.
Should You Turn Your Boiler Off When You Go Away?
If you are away from home for a few days or weeks, you may be able to reduce your heating schedule or use your boiler’s holiday mode.
However, it is usually not advisable to turn the boiler off completely at the mains during colder months, especially if there is a risk of frost. Many boilers and heating controls include frost protection settings designed to help protect your pipework in very cold weather.
Always check your boiler manual or speak to a qualified heating engineer if you are unsure. If you are considering ever changing to a heat pump, you may find this article useful which covers the same topic,
Final Thoughts
For most homes, leaving the boiler powered on in standby is fine. But leaving the heating schedule running all day is not usually the most efficient way to heat your home.
A better approach is to heat the rooms you need, when you need them. When you are out, or when rooms are not being used, they can often be left at a much lower setback temperature.
Good insulation, sensible schedules, a thermostat and room-by-room heating controls can all help reduce wasted energy while keeping your home comfortable.
If you want more control over how and when each room is heated, WundaSmart zoned heating controls can help you manage your heating on a room-by-room basis.
FAQs
Should I leave my boiler on all day?
You can usually leave your boiler powered on standby. The bigger issue is whether your heating is running all day. Your boiler only significantly uses energy when it fires to heat your home or hot water.
Is it cheaper to leave heating on low all day?
In most homes, no. It is usually more efficient to heat your home when needed, rather than constantly replacing heat that is being lost throughout the day.
Should I turn my boiler off at night?
You usually do not need to turn your boiler off at the mains overnight. Instead, use your thermostat, timer or heating controls to manage when your heating comes on.
Should I turn my heating off when I go on holiday?
You can usually reduce your heating schedule or use holiday mode. In colder weather, it is sensible to keep frost protection active to help protect your pipework.
Do smart heating controls save energy?
Smart heating controls can help reduce wasted energy by giving you better control over when and where your heating is used. Zoned controls are especially useful because they allow you to heat individual rooms at different times and temperatures.