Boiler Timer: How to Set Timer on Boiler + Common Problems

The timer on a boiler is one of the most critical components. But it is also one of the parts most prone to going wrong. In this short guide, we will explain some of the most common problems that can affect your boiler timer and show you some quick fixes that can help to fix them.

A boiler timer is important for making sure that you are getting central heating and hot water when you need it. But timers can easily go wrong and when they do it is extremely frustrating.

If you can diagnose the correct issue with your boiler timer, it is often quite simple to fix it. Several of these fixes are DIY things you can do for free without incurring the expense of calling out an engineer.

In this guide, we seek to highlight all the most common problems and how to fix them. It’s well worth spending five minutes of your time to read through – it could end up saving you a ton of money!


How Your Boiler Timer Should Work

The boiler timer is the component that tells you boiler when to be ready to produce hot water and central heating. Most people will set these to the peak times of day, in the mornings and evenings, when they are at home and likely to be washing.

But, if your boiler’s timer develops a fault, it is likely that your boiler won’t be heating your radiators and generating hot water when you need it to. There are several other possible symptoms of a timer issue too including:

  • The Boiler is working but radiators are cold
  • The Boiler isn’t working at all.
  • Boiler switches itself on and then straight off again
  • Heating is hotter or colder than it should be

All of these things can be caused by timer issues. But just to complicate matters, they can also be caused by a host of other things as well including:

  • Your Central heating system is blocked up with sludge
  • The Boiler ignition leads are broken and need replacing
  • Issues with the printed circuit board (PCB) that runs the boiler
  • The thermostat is located in the wrong place or otherwise has a problem.

Evidence of Boiler Timer Issues

While it can be tricky to ascertain whether your problems are caused by your boiler’s timer or not, there are a few tell-tale signs that can indicate whether this is the case or not. These include:

  • Boiler coming on at the wrong time – have the settings been changed or have the clocks recently gone forwards or backwards by an hour?
  • Thermostat connection – IF there is a problem with the connection between the thermostat and the timer, this could mean the boiler is not being told when to turn on.

Quick Fixes For Boiler Timer Issues

If you have problems with your boiler that you suspect are as a result of issues with the timer, there are a number of quick fixes that you can try. In this section, we will outline the most common fixes that we have found help to resolve boiler timer problems:

#1 – Check the Time Settings

Firstly, and most obviously, you should check your timer to make sure it is set to the correct times. If the clocks have recently changed, or you adjusted the timer because you went away for a few days, it is possible you just need to reset the times again.

Times can also be affected if you have recently had electrical work done in the house as this could affect the time reading on the device.

A quick look should tell you if this is the problem and by resetting the timer, the issue should be resolved.

#2 – Check the Power Supply

The next thing to check is the power supply to both the thermostat and the boiler.

Thermostats are sometimes hardwired but can be battery powered too. Check whether the batteries need changing and if they are hardwired, make sure you haven’t tripped a switch in your fuse box.

You should also check the power supply to the boiler too. A blown fuse of a tripped switch in the fuse box could cut power to the whole boiler. If so, flip the switch or replace the fuse and the problem should be fixed.

If the problem continues, it could be a wiring issue. If that is the case, you will need to get a qualified electrician out to take a look.

#3 – Check Your Heating & Hot Water Settings

Another obvious one this, but it is a good idea to check your heating and hot water settings to ensure you haven’t inadvertently changed the wrong setting or adjusted them incorrectly.

It is possible that you, or someone else in your house, has adjusted things and made changes that are affecting when you get the correct heating and hot water.

If this has happened, simply changing these settings should fix the problem.

#4 – Thermostat Issues

It is quite common for problems that appear to be caused by the timer to actually be the fault of a dodgy thermostat.

Thermostats are rather flimsier than timers and far more prone to going wrong. Their job is to measure the temperature in your property and if it falls below a certain level, send a message to the boiler that will then start the central heating.

However, if the thermostat has developed a fault, it might not be sending these messages when it should.

Another issue can occur if the thermostat is not located in the correct place. For example, if it is too close to a radiator, it will think the room is hotter than it actually is. If it is situated in a draft, it might think the room is colder than it actually is.

If you have found your central heating is coming on either too often or not enough, you might want to consider moving your thermostat to see if this resolves the problem.

The ideal location for a thermostat is one that is:

  • Away from windows and doors to avoid drafts
  • Away from radiators, towel rails, ovens, and other heat sources.
  • In a room that you use regularly where the heating is on – such as the living room
  • At approximately shoulder height to measure the temperature as you feel it

It is also possible that your thermostat could have developed a fault. If this is the case, it is usually best to get a qualified engineer to install a replacement. They are not terribly expensive and it is usually cheaper to buy a new one than fix an existing one.

#5 – Reset your Boiler

If the problem is with the boiler timer, this is built into your boiler and is rather fiddly to get to. The best option is to reset your boiler to see if this fixes the problem.

Almost every boiler model will have a reset model on or close to the display panel, If you cannot locate one, check your boiler manual to see how to reset it.

Once the boiler resets, the timer should revert back to Midnight. You will then need to manually reset this to the correct time. After that, your boiler’s timer will hopefully begin working properly again.

What to Do If Your Boiler’s Timer Still Isn’t Working

If you have worked through all of these quick fixes and the timer still doesn’t seem to be working properly, it is time to call in the experts.

It could be that the issue is more serious than it first seems. An engineer will be able to run various diagnostics to identify the problem and advise you on the best possible fix.

It could be that a major component such as the printed circuit board (PCB) has blown. If so, this could be quite an expensive fix. If your boiler is old and out of warranty, you may well want to consider buying a whole new boiler.

Be sure to get plenty of quotes before making any decisions about this to ensure you are paying the right price.

We recommend you take a look at WarmZilla as part of this process. WarmZilla is an online boiler installation company that offers some of the cheapest prices around on a whole host of top-quality boilers from the best manufacturers.

Their website is easy to use and they have loads of special offers available too.

You should get plenty of quotes, but make sure one of them is from WarmZilla.


If you have a problem with your timer, there are a number of quick fixes you can try to solve the issue on your own.

In this guide, we have highlighted some of the best and explained how they work.

If the problem persists, you will need to get a qualified engineer out to identify the root cause. If it is a major component in an older boiler, consider investing in a new one. We have recommended WarmZilla as a great place to get a quote.

Have you had any issues with your boiler timer? Did our guide help you resolve it? Do you have any tips we haven’t covered here or any questions about your own problem?

If so, please do leave us a comment using the box below. We always attempt to respond to every one.

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