Why does my boiler keep turning off?

Before you begin, make sure you know what type of boiler you have and the model. Combi, system, and regular boilers can all react differently when something goes wrong. Identifying your boiler type will help you get to the root of the problem faster.

It's just as crucial to know the boiler model as it is to see if the digital display is showing a fault code, since different boiler models have distinct codes that signify various issues.

Do different boiler types shut off for different reasons?

Yes, the type of boiler you have can affect how and why it turns off. Here is a quick overview of the main types found in UK homes:

• Combi boilers provide hot water and heating from a single compact unit. These are common in smaller homes and flats where there is less hot water demand.
• System boilers store hot water in a separate cylinder but do not require a tank in the loft. They suit homes with higher hot water demand.
• Regular boilers (also known as heat-only or conventional boilers) use both a hot water cylinder and a cold-water tank. They are typically found in older or larger homes.

Modern gas boilers are built with safety features that automatically switch the system off when a fault is detected. This prevents further damage and helps keep your home safe.

Each boiler type is built differently, which means they can respond to faults in different ways. However, some issues are common across all systems. The key is to understand how your boiler normally operates and pay close attention to any changes in performance.

• Combi boilers are more likely to shut down due to low water pressure or a frozen condensate pipe.
• System boilers may turn off because of issues with the cylinder thermostat or internal pressure sensors.
• Regular boilers might stop working if there is an airlock in the feed tank or a problem with motorised valves.

Knowing which system you have will make it easier to narrow down the possible causes. The good news is that many of these faults are minor and easy to fix. Some just need a quick reset or pressure top-up. Others may point to something that requires an engineer. Let’s break down the most common reasons a boiler shuts itself off and what you can do about them.

When to call a heating engineer

Some faults are not safe to deal with yourself. If your boiler is leaking water, producing a burning smell, or making loud banging or clunking noises, it is time to call a registered engineer as quickly as possible. The same applies if you smell gas, see the same error code repeatedly, or have already tried basic troubleshooting without success . These signs often point to deeper issues that require professional attention.

You should also check your carbon monoxide alarm regularly. If your alarm sounds, always take it seriously. Avoid turning any lights or electrical equipment and open all the doors and windows in your property. Leave the premises and quickly as possible and call the National Gas Helpline immediately on 0800 111 999.

Regular servicing is also important, as it helps prevent breakdowns and keeps your system running safely and efficiently. A qualified engineer will check all the key components and make sure your boiler is working as it should.

Recurring boiler problems? It might be time for a replacement

If your boiler keeps turning off despite regular servicing and repairs, it could be a sign that the system is nearing the end of its life. Older boilers are more likely to suffer from pressure drops, internal corrosion, faulty sensors, and inefficient performance. These recurring faults not only cause frustration but can also increase your energy bills and the cost of ongoing maintenance.

In some cases, replacing the boiler with a newer, more energy efficient model is the more cost-effective solution. Modern systems are built with improved safety features, better energy efficiency and smarter heating controls, helping you avoid repeat problems while keeping your home warm and your heating bills under control.

At Glow-worm, our range of A-rated boilers are designed to give you reliable, energy-efficient heating that fits your home and your lifestyle. Browse our full catalogue of combi, system and regular boilers.