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Boiler Timer Not Working and How To Fix


Although boiler timer faults sound easy, they can be the most confusing. They can fool even the savviest technicians. Nonetheless, don’t worry. We’re to help you crack the code and save your boiler.

Boiler timer faults are most prevalent in older boilers. By older, we’re referring to boilers that are at least 7 years old. The first symptom you’re likely to come across is your boiler randomly turning on off without your input. Eventually, it will one day shut down and refuse to turn on.

A boiler that refuses to turn on can be tricky to diagnose. There are so many components that might have gone wrong.

How sure are you it’s the timer that is failing? Continue reading to find out.

How to fix a faulty boiler timer

Check and adjust the boiler timer

Indeed, most of the boilers today are high-tech and have their own “time awareness.” Nonetheless, sometimes, this “awareness” can fail. When that happens, the timer might find itself several hours ahead or behind.

Such an inconvenience is most likely to happen after a power outage. Additionally, it can also occur if you’ve recently adjusted your household’s wiring system (Maybe you were installing a new appliance or something. These days, upon an interruption, most boilers will automatically reset their “internal clocks” to midnight.

Check for boiler power-related issues

Maybe your boiler isn’t receiving enough power. This solution best applies to situations when the boiler doesn’t come on at all.

Although we wish you to fix the problem without calling us, handling gas boilers is risky. The only thing you can do is replace the fuse in the switched spur.

If that doesn’t work, we advise you to hand over the problem to a certified Gas Safe heating engineer.

Diagnose and fix the thermostat

Thermostats and boiler timers are like couples. The relationship won’t work if either of them is at fault. Sometimes, it might not even be the boiler timer. It might be the thermostat that’s causing all these problems.

It’s surprisingly common for thermostats to fail. After all, they’re relatively “weaker” than boiler timers. Timers are more robust since the majority are built into the boiler and are hard to access and replace.

Once again, to understand a faulty thermostat, you need to know how a healthy one operates.

Thermostats are like “communicators” or “mediums” that sense room temperatures, and relay the information to boilers, thus telling them when to turn on or off.

Once you’ve set your ideal temperature setting, the thermostat will monitor the indoor temperatures. If they fall below the setting, it will trigger the boiler and direct some heat to the room.

If the thermostat is faulty, the boiler won’t be able to react to room temperatures.

“How to diagnose and fix a faulty thermostat” is a topic for another day. For today, we’ll offer one solution that can help solve your problem.

Try relocating the thermostat. This solution might work if you find your boiler timer to be correct. However, there still appears to be something wrong with the timing and heat intensity. For example, you might be receiving too much or too little heat than expected.

Rules for thermostat placing:

  • Avoid locations close to heating sources like radiators and ovens). The thermostat will communicate to the boiler that the room is hotter than it is.
  • Avoid windows and doors. The cold wind from outside will trick the thermostat that the room is colder than it is.
  • Ideally, you want the thermostat at shoulder height.

Reset the timer

Sometimes all your timer needs is a nice reset to set everything straight. Resets will help solve any software and hardware glitches. Afterwards, you will set the correct time and settings.

We are aware that there are two main types of boiler timers, manual and digital timers. Don’t worry. We’ll explain how you can reset them.

How to reset manual timers

Manual timers are sometimes also referred to as standard timers.

To reset a manual timer, you need to first look for and click the “reset” button. Some of them have switches and others levers.

After resetting, go ahead and set the correct time. Most have a dial that moves clock-like arms.

Next, program your heating schedule. Standard timers are “traditional” and, therefore, have manual dial tabs. Usually, each pin represents 15 minutes, and you activate them pushing inwards. Simply slide the times you want your boiler to start.

Finally, don’t forget to activate the timer function. The timer function is similar to the “confirm” button in digital timers.

How to reset digital timers

Most modern boilers come with inbuilt digital timers. Most of the time, there’s a touchscreen that allows you to access the program. You can research your model online to figure out the reset command.

First, make sure the boiler time is correct. Indeed, most come with auto-update functionalities. Nonetheless, it’s always good to confirm. If it’s not correct, you can consult your user guide on resetting your boiler time. Be careful with the “AM-PM” time format.

Next, set your preferred schedule. Once again, different models have differing procedures. Consult your user guide. Generally, you should see a button or section written: “set schedule.” Most digital timers are super flexible and allow you to adjust different hours, days, and even weeks.

Finally, once again, don’t forget to confirm and save your settings.

Note:  If everything else fails, you can reset your boiler or entire central heating system. We advise you to research online or consult your user guide for the procedure. Remember to be patient, boiler resets take quite some time.

How does a healthy boiler timer work?

Tricky problems deserve clear elaborate solutions. To understand a broken boiler timer, you need to understand how a healthy one operates. From there, we’ll discuss how you can fix it.

For this situation, we’re assuming you own a combi boiler. After all, it’s the most common boiler type in the UK.

Combi boilers produce heat and hot water instantly. You should receive warm water and heat the moment you open your taps and radiators, respectively. That’s all it takes to figure whether or not your timer is working as expected.

Sounds obvious, doesn’t it? When diagnosing boiler timers, responsiveness and consistency are the most important factors to consider.

How does a faulty boiler timer behave?

They undermine the very essence of responsiveness and consistency. Below are some of the symptoms you might be experiencing.

  • The boiler might appear to run well. However, you might have noticed no heat in the radiators and hot water from the taps.
  • The boiler appears to be dead. It’s not working at all.
  • The boiler is sliding in and out of consciousness. It turns on and off.
  • The temperatures aren’t correct. They’re either too high or too low for your liking.

Indeed, all these symptoms might hint at a fault boiler timer. However, that isn’t always the case. Many other components can trigger the same symptoms. If you’re not careful, you might waste money on unnecessary repairs.

Below are some boiler-specific symptoms you should look out for:

  • The boiler starts unexpectedly late or early. For example, the boiler starts its operation one hour before or after the time you’ve set. Most of the time, something might have automatically altered the setting.
  • The timer and thermostat aren’t communicating.


Timer-related faults can be tricky to diagnose and fix. They share the same symptoms with other faulty components. Nonetheless, we hope that this article has given you some insight into the issue.

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