Let's face it, there is never a good time for your boiler to stop working – after all, even if you don't need your central heating running at full blast, you are still likely to need hot water.
"Unexpected boiler problems or malfunctions are never fun," picks up Gordon Chalk, MD at Next Level Underfloor Heating and Screed Solutions LTD. "Fortunately, boilers typically present obvious warning indications of danger. Early detection of these signs may prevent a chilly house and save money on repairs."
Even though temperatures might be on the rise, understanding the signs that can point to an imminent boiler breakdown is the best way to stay one step ahead – here's what to be on the lookout for.
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Along with Alan Houghton, Gordon is managing director at Next Level Underfloor Heating and Screed Solutions LTD where he helps property owners get warmer and more comfortable with underfloor heating and proper floor screed.
1. You hear strange noises coming from your boiler
This is such an easy one to pick up on as it requires no visual inspection – simply be aware of any strange noises coming from your boiler and central heating system.
“If your central heating is making loud banging noises, this is often a sign of low pressure in your boiler," picks up Ian Palmer-Smith, supplier and heating service director at Domestic & General Domestic & General. "Luckily, this is a fairly common issue that is easy to tackle. You’ll need to check the pressure gauge on your boiler control panel. If this reads below 1 bar, increase it slightly to 1.5-2. If the pressure is any less than 1 bar it could mean less heat being transferred to the areas in your home where it’s needed. As a general rule, anywhere between 1.5-2 is usually the sweet spot.”
There are other sounds to take note of too, as Gordon Chalk explains. "Gurgling may indicate air in the system or low water pressure, while banging may indicate limescale development in the heat exchanger, reducing water flow," continues Gordon. "Whistling or 'kettling' indicates limescale or detritus.
"A professional power flush to clear sludge and limescale may be required for banging or kettling," adds Gordon. "While not this is not a DIY job, detecting the sound fast enables Gas Safe engineers to be called before serious harm occurs."
Ian Palmer-Smith is a supplier and heating service director at Domestic & General and a domestic appliance service and repair expert with over 35 years of professional experience.
2. The pressure keeps dropping on your boiler
Always keep an eye on your boiler's pressure guauge – it is a great indicator of any potential issues. You can normally find this on the front of your boiler. It may have green and red sections that show when the pressure is too low, too high or spot on.
"A clear warning indication is boiler pressure dropping," says Gordon Chalk. "Compound pressure decreases on the boiler's pressure gauge indicate a problem. An issue exists if the pressure gauge needle repeatedly drops below 1 bar, necessitating frequent repressurising.
"To repressurise their boiler quickly, homeowners can consult its handbook for filling loop instructions," continues Gordon. "Having to repressurise more than once a month signals a system leak or a malfunctioning pressure release valve. You should call a Gas Safe professional to find and fix the leak or replace the broken part before it causes serious water damage or boiler failure."
3. Your boiler is randomly turning on and off
Noticed your radiators have suddenly stopped working or that your hot water hasn't heated up? If your boiler keeps suddenly turning on and off, both could happen – and this could be an indication of a few tweaks being required.
“If you’re noticing your boiler is turning on or off sporadically throughout the day, you may need to simply adjust your timer settings using your boiler manual for help," points out Ian Palmer-Smith. "Also, check that the central heating dial is turned up too in case this has been accidentally knocked. Additionally, double check your thermostat settings. If temperatures in the home are set lower than 20 degrees, your boiler may not come on so increase the temperature slightly and you should notice better performance.”
However, this could also point to some other, more serious issues, according to Gordon Chalk.
"Unexpected boiler shutdowns and error codes can indicate a safety lockout due to a problem," says Gordon. "This causes the boiler to often shut down and show a problem code on its digital display, needing repeated resets. A reset may fix a brief malfunction, but recurrent lockouts indicate a problem with water pressure, a clogged flue, or a defective thermostat or pump. Recording the fault code and notifying a Gas Safe engineer promptly is critical. Ignoring repeated lockouts can lead to boiler failure, which might be costly to fix."
4. A red light has appeared on your boiler
Red lights are rarely a good sign – so if you see one appear, be that on a combi boiler or a different type of system, take heed.
"If you’ve noticed a red light appear on your boiler, this usually signals an error with the appliance – but this typically only requires a quick reset," reassures Ian Palmer-Smith. "The boiler reset button should be on the front panel and easy to identify.
"If the error persists, try turning the appliance off and on," continues Ian. "If this still continues, reach out to an engineer who will check if there is a bigger underlying problem. For households with boiler cover, inspecting your boiler is also a good opportunity to check what your policy includes and ensure your annual service is booked in.”
5. You see sooty black marks appearing
If you notice even the faintest of sooty black marks appearing on or around your boiler, you need to take action fast – this indicates a problem that could potentially be very dangerous.
“Sooty black marks on your boiler may indicate the start of a serious combustion problem, which can be highly dangerous if left untreated, and most certainly indicate that your boiler is heading for a breakdown," says Martin Garbutt, head of technical governance at Ding. "If you detect such marks, contact a Gas Safe Registered engineer as soon as possible.”
Sooty marks can mean your boiler is not burning fuel properly which can, in turn, lead to carbon monoxide leaking into your home. Turn your boiler off immediately, open windows for ventilation and call a Gas Safe registered engineer or, if your boiler is oil, a qualified technician.
Martin has more than 30 years' experience in the gas industry, so he knows a thing or two about boilers and heating systems. He worked for the gas regulator CORGI, before moving into the private sector in 2009 to oversee gas compliance matters on the Government’s flagship energy scheme, Warm Front.
He's recognised in the gas industry with an Incorporated Engineer status and he's currently a member of the Gas Utilisation Committee with the Institution of Gas Engineers and Managers (IGEM). Martin is a fully qualified gas incident investigator and has a proven track record of competence through the national Accredited Certification Scheme (ACS) in domestic, non-domestic and Liquefied Petroleum Gas (LPG) gas installations.
Each of these alarms comes fitted with 2x AA batteries, as well as a 7-year warranty. They detect just 50ppm of CO in the air so you can rest assured there are no leaks in your home.
6. A strange smell is detected and the pilot light colour changes
Another potentially very serious issue here – be alert to odours and keep your eye on the colour of your boiler's pilot light.
"A weird scent or pilot light colour shift are major warnings, especially for gas boilers," says Gordon Chalk. "A gas leak is indicated by a strong, peculiar smell like rotten eggs or sulphur, and an orange or yellow pilot light indicates incomplete combustion.
"If a gas smell is detected, the gas supply must be turned off, windows and doors opened, the property vacated and the gas emergency service provider (National Gas Emergency Service in the UK) and a Gas Safe engineer called from a safe distance without electrical switches," continues Gordon. "An orange or yellow pilot light may create carbon monoxide, requiring rapid Gas Safe engineer evaluation and repair – maybe boiler replacement. Do not delay or try to DIY fix these difficulties."
7. The boiler isn't firing up as it should
And, finally, if you find that your boiler just isn't firing up as it should, particularly if the weather has been cold, there could be an issue with the pipes freezing.
“A boiler that isn’t firing up as expected, or making gurgling noises when doing so, can be a sign of frozen condensate pipes," explains Ian Palmer-Smith. "This will only occur if the weather is particularly cold, usually in the peak winter months. If this is the case, the best approach is to carefully attempt to warm the pipes back up by applying a hot water bottle directly to them.”
Other techniques that can work well is to wrap warm towels around the pipes or to use a hairdryer on a low setting.
FAQs
How can you prevent a boiler breakdown?
In an ideal world, your boiler would never break down or cause you issues. Along with familiarising yourself with the signs a problem is brewing, what else can you do to keep it running in peak condition and ensure you don't have to face new boiler costs?
"Having an annual boiler check should help to prevent any issues with the appliance," says Ian Palmer-Smith.
"Your boiler should be serviced once a year for safety, economy, and to keep your guarantee current," adds Gordon Chalk. "With this regular check-up, experienced engineers can find and fix small problems before they get worse and cost a lot to fix. It also keeps the boiler running as cleanly and efficiently as possible, which is good for the environment and your wallet."
While these are the most common and obvious signs something could be wrong with your boiler, it really does pay to make sure you understand what the different types of boiler available are – all have different maintenance requirements and operating systems. It will also help when it comes to choosing a new model.
