When it comes to the most used household appliances, boilers tend to rank on top. The primary purpose of a boiler is to function as a heater and provide you with hot water. Whether you’ve been in your home for many years or a matter of months, faults with your boiler can go unnoticed unless the heating suddenly stops working like it should or your water isn’t warming up.

If you’re faced with a boiler breakdown, the experience can be both costly and frustrating, especially during the middle of winter. What’s more, some failures can be a health hazard to you and your family if you don’t spot them in time. To ensure your boiler is in good working order, here are some tell-tale signs that it may be time to replace your existing one.

Radiators Take Longer to Heat

When there’s a chill in the home, the first thing you’ll likely do is switch on your heating. If you find your radiators aren’t heating up or taking longer to heat than normal, this is a likely sign something is wrong with your boiler. In the dead of winter, you’ll want your radiators to emit heat as quickly as possible, so if this isn’t happening, it could be down to unequal heat distribution.

Your boiler may have a sludge build-up too which may be preventing your radiators from heating up. To rectify this issue, you could try bleeding your radiator or flushing the system. If this doesn’t work, it’s definitely time to consider replacing your boiler.

new boiler

Bad Smells

For those who pride themselves on having an excellent sense of smell, you’ll know something is wrong with your boiler right away if it’s giving off strange smells. Healthy boilers will never emit any odour. It’s important you look into this problem immediately.

This is because carbon monoxide can leak into your home and be extremely dangerous and even fatal to you and your loved ones. While carbon monoxide is odourless, a smell can be created because the leak is causing your boiler to not burn correctly. Even if you notice a faint smell, don’t hesitate in contacting a professional to come to check it out.

Increase in Energy Bills

When the energy bill arrives through the letterbox, you may be startled at how much you’re paying. If you find your bill is increasing month by month, this could be down to having an inefficient boiler. As your heating system ages, it can begin losing efficiency, meaning it will cost more to operate. The best way to check your boiler’s efficiency is by looking at the rating on its ErP energy level. This is a seven-point colour scale which starts from dark green (A-rated and the most efficient) down to red (G-rated and the least efficient).


If your boiler is starting to leak or drip, this is a sign your pressure or pump valve may be broken from your boiler pressure is too high. Also, corrosion over the months could result in leaks around the pipes and tank. You’ll normally be able to replace it if only a single valve of your boiler has corroded. However, if the corrosion has spread, it may be time to invest in a brand-new boiler. Never ignore a leaky boiler. Over time, this can cause extensive water damage which can be costly to repair and resolve.

Strange Sounds

If your boiler is making unusual sounds, this could signal an underlying structural problem. This occurs from the loss of pressure over boiling kettling. Another cause could be because of excess air in the unit. If you hear a banging noise coming from your boiler, this could signal a pump failure. Humming noises are normally triggered by a faulty central heating pump or thermostat.

Understandably, strange sounds from your boiler can be a nuisance to put up with. Rather than ignoring them and sticking your headphones in, it’s time to speak to a professional and have your boiler examined. They may suggest you purchase a new boiler as a result, such as a combination boiler. The Federation of Master Builders has a list of combi boilers you can check out. Their guide compares combi boiler price ranges, efficiency ratings, and output ratings.

No Hot Water

Most homeowners use hot water each and every day. From doing the washing up to taking a shower, we rely on hot water more than anything when it comes to the daily running of a home. This means if you turn your hot water tap on and find no heat is coming out, this is a sign that your boiler needs replacing. A lack of hot water from your boiler could be because of a broken diaphragm or faulty thermostat. Your boiler may be suffering from frozen pipes or low flow rates too. Regardless of the reason, it’s advised to call out a qualified engineer to take a closer look.

low boiler pressure

Loss of Pressure

Your boiler may be losing pressure constantly, which could compromise your entire central heating system. The reason for this could be because of a water leak, or standard wear and tear. Thankfully, this is a fault that is relatively simple to diagnose. If your boiler hasn’t got good pressure, it won’t function properly. Therefore, having an expert replace any low water pressure boiler should be your first step.

Pilot Light Has Gone out

A boilers pilot light can go out for all kinds of reasons. One of the main is being a broken thermocouple. This could be stopping the gas supply to your boiler, or a deposit may have built up within the pilot light. It’s possible to reignite the pilot light by yourself. However, a faulty pilot light may mean there are more underlying problems with your boiler. Speak to a professional first as they may suggest you need to have your boiler replaced.

Over 10 Years Old and no recent gas safety certificate

One question you may have is how long does a boiler last? The answer to this varies depending on the kind of boiler you’ve got. In general, there is a greater risk your boiler needs replacing once it reaches the 10-year mark. This means if you’ve been in your home for over a decade, it’s probably time to get your boiler changed. The average boiler life span tends to be between 10 and 15 years.

It’s also important to ensure that your boiler is serviced regularly, as this can help to identify any potential issues before they become a problem. Having your boiler serviced every year is the best way to ensure that it is operating safely and efficiently. A boiler service typically includes an inspection of the entire system, including the flue, the pressure, and the heat exchanger, as well as testing for carbon monoxide. The cost of a boiler service will depend on the size of the system and the complexity of the work required.

Even if you believe your boiler is fine and working properly, there’s an increased risk of problems arising as it ages. If you’ve no had a Gas Safety Certificate recently (a legal document issued by a Gas Safe registered engineer that confirms your gas appliances have been checked for safety and are working correctly), then you need to call in the experts. The certificate is required by law in the UK for all rented properties that have gas appliances. The gas safety certificate cost varies on location, and the complexity of the service.

Keeps Switching Off

If your boiler keeps switching itself off, it may be time to look at getting it replaced. Your boiler could be switching off for a number of reasons. These include a lack of water flow, low water pressure, or your pump isn’t circulating water properly. This is a serious issue that you shouldn’t ignore.

If you have any faults with your boiler like those listed above, you mustn’t ignore them. Instead of burying your head in the sand and putting it off, it’s time to call in a professional to take a look at your boiler. Not only can a faulty boiler be a nuisance and leave you with no heat, but there is also a risk of carbon monoxide poisoning which could prove fatal.

One task to do today is to go and check your boiler. If you notice anything unusual with yours, don’t hesitate to take action and get it fixed or replaced.