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How to set a boiler timer

Summary of topics:

Setting a mechanical boiler timer

Setting a digital boiler timer

Many modern boilers have timers that can be set to turn the central heating on at certain times of the day. These timers vary between mechanical timers and digital timers.

Setting a mechanical boiler timer

A mechanical boiler timer, also known as an analogue timer, is usually a round dial with a 24-hour clock in the middle. There are pins around the outside of the dial, each one indicating a period of 15 minutes, and an adjustable arrow used to point to the current time of day.

To set a mechanical boiler timer, follow these steps:

1. Make sure the dial arrow is pointed to the current time

As we progress through the seasons, hours move forward and backwards. One design flaw of mechanical boiler timers is that they do not always update automatically in line with the hours changing, resulting in the central heating system turning on too early or too late. Ensure that the dial arrow is pointing to the correct time.

2. Push the pins in at the times you want the boiler to turn on

When pushed in, the pins around the side of the dial turn the boiler on during that time. Push the pins in at the time you want your central heating to come on. For example, you may want to have a warm home between 7:00am-8:00am. If so, push the six pins in between 6:30am and 8:00am. Set the timer to switch the heating on around 30 minutes before your desired time of a warm home, allowing your heating time to sufficiently circulate around each room.

3. Set the mechanical timer to timer mode

There is a switch on mechanical boiler timers that you can turn on or off. This switch will usually be labelled ‘Timer’ and it will make your boiler turn on at the times you have chosen. If this is turned off you will only have the option to turn your boiler on or off manually.

Setting a digital boiler timer

Digital boiler timers are becoming increasingly popular due to their user-friendly interface. There are a wide range of digital boiler timers available, each with a unique set of buttons and instructions. Always refer to your user manual to ensure you set the timer up correctly. Nevertheless, there are usually several common steps that you can follow.

1. Set the correct date and time

The first step is always to make sure that the digital boiler timer is set to the correct date and time. This can be done automatically, but it is best to check to make sure that your boiler turns on at the correct time.

2. Activate the scheduling feature

Once the timer has been set to the correct time, it’s time to switch it to scheduling mode. This will allow you to set it to turn on and off at specified times.

3. Select the days and times you want the boiler to come on

The digital display will then allow you to choose when you want the boiler to turn on. You should specify a time in the morning and in the evening, such as 6:30am-8:00am and 17:30pm-20:00pm. This should heat your home to a comfortable temperature.

If you are interested in installing a mechanical or digital boiler timer, browse Vaillant’s range of boiler controls.


  • Mechanical boiler timers usually feature a 24-hour round dial with pins around the outside marking 15 minute intervals. Setting a mechanical timer involves pressing these pins towards the centre of the dial at the time of day that you want the boiler to turn on.
  • Digital boiler timers are becoming increasingly common because of their usability. Setting a digital timer involves setting it to the correct time and date, activating the scheduling feature and selecting the day and time you want the boiler to turn on.