How to set your boiler timer (and use it efficiently!)

31 March 2021 | Aimee Tweedale

One of the best things you can do to save energy at home is to only turn your heating on when you really need it. It’s a win-win: you save money on your heating bills, and lighten the load on the planet, too.

Most boilers come with a timer, which you can use to program your heating to switch on and off automatically at particular times of day. But how do you set a boiler timer?

Children at home in front of the radiator

If you’re stumped by all the buttons and switches on your combi boiler, don’t worry. In this guide, we’ll take you through what mechanical and digital boiler timers look like, and how to set them. 

What is a boiler timer?

A boiler timer, or boiler clock, allows you to control what time of day your heating and hot water turns on and off. 

If you have an older heating system, the timer might look like a small clock or dial on the front of your boiler. This is called a mechanical timer.  

Or, it might look like a small digital screen. This is what’s known as a digital timer.Whatever kind of boiler timer you have, we’ll show you how to use it. 

How does a boiler timer work?

To give you a really in-depth answer to this question, we’d need to know exactly what brand and model of boiler you have. But there are some rules of thumb for most common gas boilers.

In general, boiler timers allow you to make sure your heating turns on at the same time every day.

Want even more control over your heating, with different temperatures for different rooms? Read all about smart thermostats, and how they could save you money.

A mechanical boiler timer

Benefits of setting your boiler timer

  • Save money. Making sure your heating is only on when you need it is the best way to trim some extra cash off your energy bills. 
  • Reduce your carbon footprint. Heating is one of the biggest sources of carbon emissions in the home. So by switching it off as much as possible, you’re doing your bit in the fight against climate change
  • Stay warm. Make sure your central heating is always on only when you need it.

For more ideas on how to save energy at home, read our complete guide to being efficient with heating and hot water.

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Common boiler timer settings

Most combi boilers will have at least 3 settings: On, Off, and Auto or Timed (this one is sometimes represented by a clock symbol). These settings might be named differently on your boiler. The basic idea is that your heating is either on, off, or following the instructions you’ve set on your timer.

These are some common settings you might see on your combi boiler timer:

  • 24 hours or On: the heating will stay on all the time, until you manually turn it off
  • Off: this one is quite self-explanatory – the heating is off
  • Auto or Twice: the heating will turn on and off at the times of day you’ve programmed it to do so
  • All day or Once: this means the heating will switch on at the time of day you’ve programmed it to do so, and then will remain on until the end of the day (or the last Off setting of the day)
  • 1 hour or Boost: this will give you a one hour boost of heating, on those extra cold days when you need a bit more warmth!
  • Advance: this setting moves the timer along to the next On or Off setting in its daily cycle

Not sure what type of boiler you’re dealing with? Read our guide to combi, system, and conventional boilers.

How to set a boiler timer

Boilers come in lots of different shapes and sizes. To find out how to use your particular boiler timer, it’s always best to refer to your boiler instruction manual. But we can give you a general overview of how most boiler timers work.

The first thing you need to figure out is whether you have a mechanical or digital timer. 

Mechanical timers look like a dial, with a traditional clock in the centre. Digital timers have a small screen, like a digital clock. 

What's the difference between mechanical and digital boiler timers

How to set a mechanical boiler timer

First things first: make sure the time is right. There will be a small clock face on the inside of the dial. Make sure it’s showing the correct, current time. 

Remember, boiler timers usually use a 24-hour clock, rather than a usual clock face. So, for example, if it’s 3.30pm, or 15.30, make sure the arrow is pointing halfway between the 15 and the 16.

Next, you need to tell the boiler what times you would like the heating to turn on. To do this, use the small plastic tabs that line the outside of the dial. These may look like little pins, or switches.

Each one of these tabs represents 15 minutes of time. Simply push the tabs in to align with the times you would like the heating to be on. Some boilers will need you to push the tabs, or pins, towards the clock face. On other boilers, you might need to push them the opposite way. Check your boiler manual, to be sure. 

It’s a good idea to choose times when everyone is likely to be home, and most in need of warmth. It’s also wise to set the boiler to come on around 30 minutes before you will need hot water, as this gives it enough time to fully warm up. For example, you could push the tabs in between 7am and 9am, and then again between 6pm and 8pm.

Finally, make sure your boiler is not set to simply On or Off, but to a timed setting. On many boilers, this may be represented by a small clock face symbol.

So, to summarise:

  • Set the boiler clock to the right time
  • Push in the tabs to mark the times of day when you want the heating to come on
  • Make sure the boiler is on a ‘timed’ setting

That’s it! It’s not as complicated as it may seem.

How to set a digital boiler timer

With digital timers, as with mechanical timers, it’s important to first check that your boiler is showing the correct time. 

There should be an option on your timer that says Set time, Set clock, or similar. Use this and the arrow keys to make sure your digital timer is showing the correct time of day.

Next, there should be a button labelled Set, Program, or something similar, which will allow you to set when you want your heating to come on. Again, use the arrow keys to cycle through the days of the week and times. 

Some boilers will need you to individually program each day of the week. Others allow you to add the same setting to every day, or to weekdays or weekends. Check your boiler manual for more specific guidance. 

First you’ll need to add the time you want the heating to turn on. Then, you’ll be asked to add the time you want it to turn off. Some boilers will let you set multiple timings in a day. Check your boiler manual, to find out how to do this. 

Finally, hit the button marked Set or Run, to confirm your changes.

In summary:

  • Set your boiler clock to the correct time
  • Select Set time or Set clock (note: it may be called something different on your boiler)
  • Choose when you’d like your heating to be on, by using the arrow keys to select days and times
  • Hit Set or Run to confirm your settings

And Bob’s your uncle! 

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How to turn off a boiler timer

Turning off your boiler timer is simple. All you have to do is make sure that your boiler is no longer on a timed setting (usually represented by a clock symbol).

If you’d like your heating to be switched off entirely, just select Off.

If you’d like your heating to be on, regardless of what time of day it is, select On or 24 Hours. Note, these settings might be called slightly different things on different boilers. It’s best to check your instruction manual to be sure.

Is your boiler timer not working?

Problems with your boiler timer can be really tricky. As it controls when your heating comes on and off, it’s not always easy to tell whether it’s the timer that’s broken, or something else in your heating system. 

If your boiler timer’s on the blink, these are the kinds of symptoms you might notice:

  • The boiler isn’t firing up when it should
  • The boiler appears to be working, but there’s no heat in the radiators
  • The heating comes on when it should, but then turns straight back off again

All of these are really frustrating problems. And to make matters worse, they could be due to a number of boiler faults – not just your timer. For more help, read our guide to common boiler problems and how to fix them, or watch our Senior Engineer Rich Laniyan walk you through the issues in our easy-to-follow video series.

If you notice that your heating’s coming on an hour earlier or later than it should, then it’s a safe bet your boiler timer is to blame. (Have the clocks gone forwards or backwards recently? If so, make sure your boiler timer is up to date!)

How to figure out if you have a broken boiler timer

Here are 5 things you should check out if you think you’re having issues with your boiler timer. If these tweaks don’t work, it’s best to call a registered engineer to come and diagnose the problem. 

  • Set the correct time. The time being wrong is one of the most common issues with boiler timers. 
  • Check your power. It’s important to rule out any issues with power. If your boiler isn’t responsive at all, it might be an electrical fault. In this case, it’s best to call an electrician.
  • Check your thermostat. If you have a thermostat connected to your heating, there’s a chance it could be this playing up, rather than your boiler timer. If you recently got a new thermostat, or moved it to a different location, then it’s likely to be your culprit.
  • Check heating and hot water settings. Of course, it’s pretty unlikely – but there’s a chance you could have turned the heating down to its lowest setting, or even off, and forgotten about it. So before you call an engineer, check all your settings are where they should be. 
  • Reset the boiler. Before you call an expert to take a look, it’s worth rebooting the boiler to see if it helps. Read our complete guide to how to reset your boiler.

Once you’ve carried out all these checks, if your heating is still playing up, you may need a new boiler timer. The best thing to do is to call a Gas Safe-registered engineer. 

Find out how OVO Energy can help keep your boiler in working order all year round.

Sources and references:

  1. Based on analysis carried out by the Carbon Trust for OVO Group (2020), 28% of an average individual’s carbon footprint in the UK comes from energy. In this analysis, the carbon footprint includes the following lifestyle categories: energy, transport, shopping, food and drink and holidays. See table below for each category. This carbon footprint data has been calculated using BEIS 2020 emission factors. This excludes emissions from things that the average person cannot directly control such as supporting the NHS, defence, government bodies, etc. Please note these figures are not reflective of potential changes to your habits during the coronavirus pandemic.