The 12-Step Boiler Maintenance Guide: Keeping Your Home Warm and Safe

15 November 2023


Welcome to our comprehensive 12-step guide to boiler maintenance. Your boiler plays a crucial role in keeping your home warm and cosy, especially during the cold winter months. In all likelihood, it’s also responsible for providing your household with hot water for washing, bathing and perhaps showering too. Regular maintenance not only helps extend the lifespan of your boiler but also ensures the safety of your family and home. In this guide, we will provide you with easy-to-follow steps to keep your boiler in excellent condition.

We should point out that many of the tasks are best performed by a professional boiler engineer. As far as the annual service is concerned, that’s a non-negotiable. You should not attempt to perform any kind of fix on your own boiler, even if it looks trivial. The risks posed by carbon monoxide, gas leaks, fire, electric shock or water leak are just too real to leave to chance.

In addition, a qualified engineer will not only make your boiler safe but also efficient. Sometimes replacing worn out parts or sensors can have a dramatic effect on the amount of heat your boiler produces for a given amount of gas. 

Step 1: Familiarise yourself with the basics

First things first – take some time to familiarise yourself with your boiler. Understanding its components, such as the pressure gauge, temperature controls and safety features, will give you a better understanding of how it works. Obviously the best time to get to know your boiler is when it’s working well. That way, you are more likely to notice that something is amiss, and take the relevant steps to remedying it.

So if it has just been installed or serviced, take a look at what the boiler looks and sounds like in its “normal” state. Listen out for what sounds it makes, and take note of what the pressure is. We’ve written about what noises you should listen out for in the article “Why Is My Boiler Making Noises?” – have a read if you’re in any doubt.

Step 2: Check boiler pressure

Monitor your boiler’s pressure gauge regularly to ensure it is within the recommended range. High or low pressure levels can indicate a problem. Refer to your boiler manual for specific pressure guidelines. Generally speaking, domestic boilers should be at around 1 bar, but if yours is a little above – up to 1.3 bar, for example – it’s probably fine. It’s possible that your boiler will withstand much higher pressures, and the manual might indicate that, but they generally work at their best at around this level.

Pressure can only really go up if you add extra water to the closed system, or if there’s a partial blockage somewhere causing localised pressure increases. You might have high pressure if you’ve just bled a radiator and then overfilled the water by accident. 

If your pressure is lower than 1 bar, it’s possible there’s a problem. That could mean a leakage caused by ill-fitting pipework or a damaged radiator valve. While you can regain the pressure by filling the system with water, it will only be a temporary measure if there’s a leak somewhere. Have a read of “Why is my boiler losing pressure?”, and give us a call.

Step 3: Bleed radiators

If you notice that your radiators are not heating up evenly, it may be time to bleed them. This process involves releasing trapped air, allowing hot water to flow freely. Doing so will boost heating efficiency.

A telltale sign that you need to bleed your radiators (or just one radiator) is if it is hot at the bottom but cooler at the top. Because water is heavier than air, the water will sink to the bottom and will continue to circulate around the boiler, staying hot. The air won’t be circulated or heated up, so while the walls of the radiators will pick up residual heat, they won’t be hot.

To bleed radiators, you need to gently release the valve at the top of the radiator with a special key or a spanner, depending on the design. You should hear it hissing like opening a fizzy drink bottle. That’s the air escaping. Eventually, the radiator will fill with water, and you can close the valve. It’s likely some radiator water will squirt out before you can react, so make sure your walls and carpets are covered!

Step 4: Monitor water levels

Regularly check your boiler’s water level to ensure it remains within the recommended range. This prevents damage caused by low water levels and maintains optimal performance. Water levels are tied up with pressure and the air trapped in the system, so the two steps above should help you to keep on top of this.

Step 5: Inspect flues and vents

Examine your boiler’s flues and vents for any obstructions or signs of damage. Clear away any debris that may block airflow, as this can lead to poor combustion and potentially dangerous situations, particularly carbon monoxide levels. Autumn and winter can be particularly prone to flue blockages. Falling leaves can quickly full up a vent, and combined with rain they can become sloppy and not blow away in the wind. In winter, even snow can block the flue if it’s particularly heavy and quick, and if it falls when the boiler is off, for example overnight. 

Even springtime can have its risks, too. This time it’s birds nesting in the nice warm vent. It’s more common than you might think, so keep an eye on the situation. The best solution is to install a guard or cover over the vent. They are a wire mesh or plastic device that fits around the vent, thus allowing gases to escape but stopping the encroachment of leaves – and birds! 

Step 6: Test carbon monoxide detectors

Safety is paramount. Ensure your home is equipped with carbon monoxide detectors and test them regularly to guarantee they are functioning correctly. Carbon monoxide is a colourless, odourless gas that can be emitted by faulty boilers and poses a severe threat to your family’s health.

Testing takes two forms. First, you’re testing that the battery and alarm are still working. You can usually do this by holding down a button, like with a smoke detector. Second, you can actually test it by exposing it to a small amount of carbon monoxide. You can buy cans of it, which you spray onto the sensor. In a well ventilated room, in a small amount, it’s perfectly safe. Check your detector’s paperwork for details of both tests.

Step 7: Schedule an annual professional inspection

While regular maintenance tasks can be performed by homeowners, it is highly recommended to have a professional service your boiler annually. A trained technician can identify any underlying issues and carry out thorough maintenance to keep your boiler in peak condition.

It’s not just for your peace of mind, safety and cost-savings, however. In most cases, your boiler’s warranty will be dependent upon having it serviced by a qualified engineer once every 12 months, starting with the installation date. In other words, if components stop working because of factory errors or some wear and tear issues, your warranty should cover replacement. But if you’ve missed a service, you might have to pay for any parts and labour that are required.

Even if you’re less than 12 months since your last service, sometimes boilers need another service sooner. That could be because you use yours a lot more than the average person, or because something has changed, such as installing a new radiator. Read “The 11 Signs Your Boiler Needs Servicing” for more information.

Step 8: Maintain clear space around the boiler

It’s not unusual for our engineers to get to a home and wonder where the boiler is! Sometimes, people forget their boilers exist and allow build-ups of clutter, from ladders and DIY leftovers to piles of clothes and even things like cabinets. It makes everyone’s job that little bit harder.

To ensure proper ventilation and prevent potential fire hazards, clear any clutter or debris around your boiler. Maintaining a clear area will also allow for easy access during inspections or repairs. Don’t forget to run a duster over the top from time to time, either. As boilers are often in kitchens or utility rooms, they can often get a coating of grease, steam and detergents, which add up to a problem if it gets bad. 

Step 9: Check for leaks and corrosion

Inspect your boiler for signs of leaks or corrosion. If you notice any issues, contact a professional engineer immediately, as leaks can cause extensive damage and compromise the safety of your boiler. Do not attempt to fix them yourself, as there’s a specific sequence of actions required to shutting down a boiler and making it safe. It’s definitely not a job for the amateur.

Step 10: Service boiler controls

Periodically test and service your boiler’s controls, such as thermostat and timers. This ensures accurate temperature regulation, prolongs the lifespan of your boiler, and contributes to energy efficiency.

If you have a manual thermostat, you should be able to hear it click when you move it, and when it clicks the boiler should turn on or off (if it’s set to turn on in response to the thermostat). 

Digital controls are a bit harder to test, but if you suspect your thermostat isn’t always controlling the boiler correctly, there could be a build-up of detritus that’s stopping it from sensing the correct temperature, or an electrical issue. Either way, get a professional to have a look at it.

Step 11: Upkeep during summer months

While your boiler may not be in use during the summer, it still requires attention. Turn it on for a short period every three to four weeks to prevent components from seizing up. This helps maintain its functionality when colder weather returns. Remember, you probably never stop using the boiler because you always need hot water, but the same doesn’t necessarily apply to radiators and towel rails. That’s especially true of a combi boiler.

So while the gas is burning and the water is flowing, the boiler might seem to be working fine. But there are components like diverter valves, which redirect the hot water from the taps or cylinder to the radiators. On some boilers, if that component isn’t used for a prolonged period, it can get stuck in one position, so one part of your hot water/central heating system won’t work. 

Just getting your radiators fired up for a few seconds can prevent this. The best way to do it is to turn the thermostat up full, so the heat comes on whatever the ambient temperature is. Make sure your boiler’s controls and timer are set to turn the heat on in such a case.

Step 12: Keep a maintenance record

Maintain a detailed record of all the tasks, inspections and repairs performed on your boiler. This record helps track your maintenance schedule and assists professionals in understanding your boiler’s history during service visits. It’s a simple thing to do that can save you time and money if anything goes wrong. It also helps to keep a proof of service record if you ever need to call in your warranty. 

Always use the professionals

Regular maintenance of your boiler is essential for both its performance and the safety of your home. By following these 12 simple steps, you can ensure that your boiler operates efficiently, saving you money on energy bills, extending its lifespan and, most importantly, keeping your family warm and safe through the seasons.

Remember, if you encounter any concerns or are unsure about any tasks, always consult with a professional technician. If you’re in the Milton Keynes area, we’re always ready to pop round and have a look at your boiler to make sure it’s working properly. We can also do your annual services and install and replace your boiler if yours has come to the end of its life or if you need an upgrade. Give us a call for any boiler-related issues.