Why do boilers fail when we first turn on the heating after summer?

Boilers have moving parts, and some of these components don’t operate during the summer when we only use hot water. These parts sit in the same position for months in a damp environment. Water quality is ideal in well-maintained systems, but in others, the conditions may not be as favourable. Your boiler might also be a few years old, which can lead to seals seeping or scaling around the components, increasing friction.

Since these parts haven’t been in use for a long time, they can become prone to sticking. Regular checks and operation of these components can extend the life of your boiler and heating system. While customers or DIY enthusiasts aren’t allowed to work on boilers directly, there are a few things you can do to keep your system in good shape, which I’ll explain here. Of course, more extensive work should be left to gas engineers.

Boilers and heating systems require regular maintenance and servicing. New boilers need this for warranty purposes, while older boilers benefit from extending their lifespan and preventing breakdowns. The best thing you can do is book an engineer for a service.

From our experience, many people neglect to service their boilers for years. We all take our cars for regular maintenance, don’t we? But somehow, our boilers get forgotten year after year.

At A Tech Installs, we offer boiler servicing to customers in the West Yorkshire area at competitive prices. We cover a wide range of checks, not just on the boiler but on the entire heating system.

In a standard boiler service, here’s what you can expect:

• Visual inspection: We check the boiler, flue, pipework, and components for signs of leaks, damage, or other obvious problems.

• Ventilation check: It’s essential to ensure there is enough ventilation for the boiler to operate safely and efficiently.

• Gas consumption test: This ensures the boiler is using the correct amount of gas to deliver the necessary power (in kW) and heat.

• Working pressure check: This confirms that enough gas is reaching the boiler and that there are no blockages or issues with pipe sizing.

• Flue flow and flue gas analysis: This test checks the condition of the flue and ensures the boiler is burning fuel safely and efficiently.

• Filter cleaning: Magnetic filters, if fitted, need regular cleaning to maintain water quality and prevent blockages.

• Condensate trap cleaning: The condensate trap needs regular cleaning as it collects the dirt and sediment that build up from the heat exchanger. A complete blockage here can cause the boiler to “suffocate” and stop working. While you might think your boiler has been fine without cleaning for years, the truth is that sooner or later, issues will occur.

  Boilers with aluminium heat exchangers tend to produce more sediment due to their higher susceptibility to oxidation, which can lead to more frequent blockages. In contrast, stainless steel heat exchangers are more resistant to corrosion, so they generate less sediment. However, even with stainless steel, there can still be some buildup over time, and it’s not uncommon to find small debris or even insects in the trap. Regular cleaning is essential to keep the system functioning efficiently and to prevent potential failures.

• Controls and safety device check: We ensure the temperature controls and thermostats are working properly. Safety devices are also checked to make sure that the boiler won’t release gas after a shutdown.

• Gas meter and pipework check: We test the gas pressures at the meter to ensure everything is operating correctly. First, we check that there is enough gas supply reaching the boiler. We also test the pressure when the gas is off to make sure the system is not over-pressurized, a function controlled by the regulator attached to the meter. This ensures that the system remains safe and operates efficiently. Additionally, we inspect the gas pipes to confirm there are no leaks, damage, or issues with support.

• System pressure check: The optimal system pressure when cold is around 1.2–1.5 bar. Low or high pressure can put stress on the boiler and the expansion vessel.

• Expansion vessel check: We ensure the expansion vessel is maintaining the correct air charge, which helps regulate system pressure.

• Radiator check: We bleed the radiators to ensure the heating system is working efficiently.

• Water quality and inhibitor level check: We take a water sample from the heating system, providing valuable insights into its condition. We visually inspect the water for cleanliness, looking for signs of debris or corrosion. Based on the test, we check the inhibitor levels, which is a chemical that prevents rust and sludge buildup. If the levels are low, we’ll recommend topping it up. However, as per industry recommendations, the inhibitor should be fully renewed (drained and replaced) every five years to ensure continued protection and efficiency within the system.

• Test fire and CO alarm check: We check that your alarms are functioning properly for safety.

• Safety checklist with recommendations: At the end of the service, you’ll receive a detailed list of findings and any recommendations for improvement or urgent repairs.

• Certificate and service record: As with every job, we provide a certificate as part of industry standards.

Full Service for Older Boilers

Boilers that are over 4–5 years old may require a full service. This involves removing and cleaning major components, such as the heat exchanger, to ensure that condensate water can flow freely through the system. Blockages here can lead to early corrosion. Stainless steel heat exchangers are less prone to corrosion compared to aluminium ones because of how they resist oxidation. However, even stainless steel can accumulate dirt and debris over time. Aluminium heat exchangers tend to create more sediment, which can lead to blockages. Keeping the heat exchanger clean not only prevents corrosion but also reduces the stress on the fan, allowing it to run more smoothly and efficiently. A cleaner heat exchanger also improves the boiler’s overall efficiency by making better use of the heat.

Different Types of Boilers

If you don’t have a combi boiler, some of the components (like motorized valves and expansion vessels) may be outside the boiler but perform the same functions.

What You Can Do to Prevent Boiler Breakdowns

There are a few simple things you can do without any tools to help prevent boiler issues. One of the most important is to make sure the boiler is run in heating mode for at least a minute or two a few times during the off-season. This keeps the components moving freely and prevents them from seizing up.

For radiators, particularly TRVs (thermostatic radiator valves), I recommend turning them all the way down to zero and back up again a couple of times a year to keep them moving smoothly.

If you have system or heat-only boilers, check isolation and gate valves every six months to ensure they’re not stuck. Operating these valves regularly can prevent them from seizing and causing problems when they’re needed most.

When Is the Best Time to Service Your Boiler?

It’s best to service your boiler before the heating season starts, at the end of summer or early autumn. Off-peak times like these may offer better prices, and engineers are less rushed, so they can spend more time on the job.

A standard boiler service should take about an hour. If it takes less time, it may indicate that only a safety check was done, not a full service. A full boiler service, done properly, can take 2–3 hours.

At A Tech Installs, we are transparent with our work. We provide not only paperwork but also photos of the tests and tasks we’ve carried out.

We hope you find this information useful. If you live in the West Yorkshire area, please be in touch or use or online booking to arrange a boiler service or sign up for our service plan.

Best regards,
Attila from A Tech Installs