Have you moved into a new house with a mechanical boiler timer, and don’t know what you’re doing with it? Don’t worry, I have a mechanical timer, so let me show you how to set a timer on a boiler. I’ve got a step-by-step photographic guide to make things as easy as possible.

I’ve written about setting the timer on your boiler in the past in order to save energy.  But the other day it dawned on me: what if you don’t know how to set a timer? Don’t worry. Let me show you how to set a timer on a boiler.

I have a combi boiler and it has one of those mechanical timers on it. Being used to digital timers I’ll admit I was a little flummoxed by it when we first moved into our house. I did a bit of internet searching and found this useful video about how to set a mechanical boiler timer. 

Video Guide on How to Set Your Boiler Timer

The video should appear above. If you can’t see the video in your browser, then here’s a direct link to the video in YouTube.

Although it is made for Worcester boilers, this video is actually really useful for most makes of boilers. It certainly did the trick for our Valiant boiler. This is because almost all mechanical timers work exactly the same, regardless of the make.

Step By Step Boiler Guide With Photos

If you can’t get the video to work, or if you would prefer a step by step guide that walks you through setting a timer at your own pace, then let me run you through exactly how to set a timer on a boiler. You’ll soon have yours working in no time:

1. Set the time on your boiler

First of all, ignore all the little tabs for now. What you need to do first is set the clock to the right time.

You can do this by turning the dial around clockwise until the arrow points to the correct time in the inner portion of the dial. It’s important to bear in mind that boilers work on the 24-hour clock.  So make sure you’ve set it to 24 hour clock time, otherwise, your heating will come out at odd hours of the night! If it’s 1:30 pm (13:30 in 24-hour clock speak) then you want the arrow to be halfway between the 13 and 14.

2. Now set the time when you want your boiler to come on

Once the time is set correctly, you can now set the times that you would like your heating to come on and go off at.

This is where the little tabs come in. These tabs on a mechanical boiler timer can be overwhelming as there are so many. However, I promise you that they are not as confusing as they look.  All that they do is represent 15 minute periods of time. 

To set what time you want your boiler to turn on, simply push those tabs in for the times that you want your heating on. Let me talk you through this, in case this sounds complicated.

After you’ve set the time properly on your boiler, you’ll notice that each tab lines up with each 15-minute segment of the 24-hour clock. So, to tell your boiler that you want your heating to come on between 5:45 am and 7:30 am, you are going to want to push in all of the tabs that represent that period of time.

Once you’ve done this you should have all 7 consecutive tabs pushed down between 5:45 am and 7:30 am. All of the other tabs should be up.

Here’s a picture of my boiler timer so you can see what I mean.

how to set a timer on a boiler

When I took the photo, the time was 1 pm so you can see that the arrow points to 1 pm (13). You can also see that my heating is set to come on twice a day.  Firstly between 5:45 am and 7:30 am (we are early birds!).  And secondly between 6 pm and 8 pm.  If you look closely you’ll notice the tabs are down at these times, and all of the other tabs are up. It can be quite tricky to see so I have annotated the photo to make this a bit clearer.

It’s quite easy to accidentally twist the dial and change the time when you’re adjusting the tabs. Therefore, you may have to readjust the time at this stage! Just something to be aware of.

3. Next Steps

Now you need to tell your boiler that you want it to run to your scheduled programme. To do this, simply turn the switch that you would normally switch the boiler on to point to automatic scheduling. This may take the form of a picture of a clock or of a stopwatch.  It will depend on your boiler – mine’s a stopwatch. Your boiler should now come on and then switch off automatically at the desired times!  And that’s how to set a timer on a boiler!

Energy Efficiency Tips

I always love a two-for-one deal. So as well as telling you how to set the timer on your boiler, do let me share with you my top energy efficiency tip for your boiler.

It typically takes about half an hour for your house to warm up once you’ve switched your boiler on.  It then takes around half an hour for your house to cool down again once it’s switched off. So, with that in mind, if you get up at 7:30 am and leave the house at 8.30 am, it’s most energy-efficient and comfortable for you if you set your boiler timer for your heating to come on at 7 am and off at 8 am.

ps: you can find lots of energy-saving tips here if you’re looking to save money on your heating bills!

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