Why do I keep having to reset my boiler?  

1 July 2024

Having to frequently reset your boiler can be frustrating and inconvenient, especially during the colder months. This issue not only disrupts your home’s heating and hot water supply but can also indicate other problems that need addressing. In short, simply doing a reset is just delaying the inevitable – there’s a problem that needs fixing.

The worst thing is that it often happens without you realising, such as when you’re asleep. You expect to wake up to a warm house and a tank full of hot water, but it’s freezing and the hot taps are running cold.

There are many possible reasons behind boiler resets, so we’ll look at the most common ones, and suggest some ways you can address them. However, we’d always recommend calling a qualified gas engineer unless the issue is down to your own actions, such as having the thermostat too low or the timer set up wrongly.

Common causes of boiler resets

In our experience, these are the main causes of boilers tripping out:

  • Low water pressure
  • Air in the system
  • Thermostat issues
  • Faulty diverter valve
  • Overheating
  • Electrical issues
  • Sensor and component failure

We’ll go through them one by one below.

Low water pressure

Low water pressure is one of the commonest reasons for boilers shutting down and needing a reset. If the pressure gauge on your boiler shows a reading below 1 bar, it’s likely that that’s the issue. Low water pressure usually results from leaks in the system or recently bled radiators, but there can also be other technical factors. Checking the pressure and topping it up to the recommended level (typically between 1–2 bars) using the filling loop can often resolve this problem, at least temporarily.

Air in the system

Trapped air within the heating system can make your boiler behave unpredictably, and give false readings to sensors. Typical signs of trapped air are gurgling noises and cold spots at the tops of some of your radiators. Bleeding the radiators to release trapped air can help restore normal operation and prevent resets.

Thermostat issues

The thermostat plays a crucial role in regulating the temperature of your heating system. It basically measures the temperature in the room, and switches the heating off when the temperature reaches what you’ve set it to.

If the thermostat is faulty or incorrectly set, it can cause the boiler to operate inefficiently or shut down unexpectedly. Issues can range from dead batteries in wireless thermostats to incorrect settings or calibration. Make sure your thermostat is working correctly and set to the appropriate temperature.

Faulty diverter valve

The diverter valve controls whether heat goes to the radiators or the hot water taps. If the diverter valve is faulty, it can cause the boiler to shut down, which often requires a reset. A common sign of a faulty diverter valve is irregular hot water supply and heating. Replacing or repairing the diverter valve might be necessary to resolve this issue.


Boilers have safety features to prevent overheating, and excessive heat can trigger a shutdown. Overheating can be caused by several factors, including a lack of water flow, blocked heat exchangers or faulty components. Signs your boiler may be overheating include loud banging noises (kettling) and fluctuating boiler pressure. Having the overheating issue fixed quickly should prevent further damage.

Electrical issues

Your boiler needs electricity to run, so electrical issues can also cause a boiler to shut down and require a reset. Faulty wiring, tripped circuit breakers or issues with the power supply can cause shut-downs. If electrical faults persist, it’s advisable to get in touch with a qualified electrician to inspect your system.

Sensor and component failures

Boilers rely on various sensors and switches (such as the flame sensor, temperature sensor or pressure switches) to operate correctly. If any of these parts malfunctions, it can cause the boiler to shut down. A common sign is error codes displayed on the boiler’s control panel. Replacing faulty sensors or components can resolve the issue and prevent frequent resets.

Preventative measures and solutions

So what can you do? We’d always recommend that getting in touch with a qualified Gas Safe engineer should be your first port of call. But if you want to take steps to prevent trips, or to diagnose the issue, there are ways you can help yourself.

Regular maintenance

Regular maintenance is key to keeping your boiler in optimal condition. Scheduling an annual service check by a qualified engineer can identify and resolve issues before they cause major problems. Regular maintenance helps maintain efficiency, safety and reliability.

Monitoring boiler pressure

Regularly checking your boiler’s pressure and maintaining it at the recommended level is crucial. Monitoring the pressure can help identify potential leaks or issues before they require a system reset.

Upgrading or replacing faulty components

Older boilers or those with persistent issues might benefit from upgrading or replacing faulty components. Investing in newer, more reliable parts can improve your boiler’s performance. If your boiler is more than about 15 years old, however, it might be time for a new one – you can end up spending more on repairs in the long run, and components for older models become harder to get hold of.

When to call a professional

While some minor issues such as bleeding and refilling can be addressed by homeowners, most situations require professional help. If you notice recurring problems despite taking the measures listed above, it’s time to call a qualified Gas Safe registered engineer. They have the expertise to diagnose and fix complex issues, ensuring your boiler operates safely and efficiently. 

Frequent boiler resets are not just annoying – they are a signal that something is amiss with your heating system. Remember that the boiler tripping is a safety measure designed into the boiler, not a problem in itself. It’s simply designed to protect the boiler from a separate fault. The only exception is when the circuitry controlling the trip mechanism has an issue – but that’s pretty rare. In the absence of any visible leaks or audible noises, the issue will be traced back to a sensor, which is often a ten-minute job to fix.

Don’t be frozen out of your own home for the sake of a minor repair – if you’re in or around Milton Keynes, call one of our Gas Safe engineers today.