Keep costs down by spotting common boiler red flags

Households are being urged to conduct simple boiler checks before the UK is hit with freezing temperatures, to ensure homes can be heated as efficiently as possible.

Data shows over 100,000 boilers breakdown annually in England, costing an estimated £32 million.*  

Energy experts at Quotezone are sharing tips to help families prepare for the colder months, save money and avoid potential issues.

Common problems like unexplained condensation around the boiler or flickering pilot lights could cost homeowners in the long run, making their homes harder to heat and causing bills to increase.

This comes after one in five Britons admitted they are worried about struggling to pay their energy bills this winter, in a survey conducted by Quotezone’s energy team.

Freezing temperatures can reduce boiler efficiency just when occupants rely most on heating and hot water, and inefficient boilers are very expensive to run.

With so many concerns about keeping on top of costs, the experts are urging homeowners to act now, spot any issues early, and get prepared ahead of the colder winter temperatures.

Helen Rolph, energy comparison expert at Quotezone.co.uk said: “It’s concerning that a fifth of households are worried about warming their homes as we enter the winter months. Though we have already experienced an initial cold snap, the chilliest temperatures are yet to come.

“We are urging all households to carry out simple checks on their boiler, look out for common red flags and get the annual service booked in.

“Poorly maintained boilers can make it much harder for budget-conscious Brits to keep their bills down. Now is the time for the pre-winter boiler MOT.

“Boilers need serviced regularly to ensure they are running efficiently and that home insurance is valid – providers usually specify once a year, failure to look after the boiler could leave homeowners unprotected should they need to make a claim.

“If people own other properties as well, they have a legal obligation as landlords to service the boiler at least once a year,** ensuring the safety and comfort of their tenants.”

Quotezone.co.uk’s boiler red flags to look out for:

1.Unexpected bill increase

If your heating bills seem to have climbed without any uptake in your usage, it could be a clear sign that your boiler is no longer working efficiently. Older models, especially those over 10 years old, often have much lower efficiency ratings, meaning they must work harder to deliver the same heat as a newer model. In many cases, replacing inefficient boilers is the best long-term investment, however, regular servicing can also help keep older boilers in check.

2.Flickering pilot light

The pilot light on your boiler should normally be a steady blue flame. If it’s yellow, orange, flickering or has gone out completely, it can indicate incomplete combustion. This is a serious safety issue that needs immediate attention. To avoid any serious issues, make sure to check the light regularly and look up your make and model of boiler online to double check the colour of a healthy flame – consult a professional with any concerns. 

3.Leaking

Any leaking or water pooling under your boiler are clear warning signs that something is wrong. If left unchecked, leaks can lead to low system pressure, which will reduce heating performance and shorten the lifespan of the boiler. Even small drips can indicate failing internal components. If you notice consistent moisture, damp patches, or unexplained puddles near your boiler, it’s important to switch the system off and call a qualified engineer as soon as possible.

4.Condensation

If you notice new or excessive condensation on windows, walls or ventilation points around your boiler, it could be a sign of a problem. If your boiler is having problems with how it is venting moisture, then warm and moisture-rich air from the boiler circulates in your home rather than being safely discarded outside. Persistent condensation can lead to wider issues like damp and mould, so it’s important to keep an eye out and tackle issues early.

5.Turning off by itself

If your boiler is unexpectedly shutting down, it’s a clear warning that everything is not functioning properly. Low water pressure, blockages, air trapped in radiators could all be to blame for your boiler randomly shutting off. Ignoring these issues can lead to inconsistent heating, making it more expensive to heat your home during the coldest days. Ignoring the problem could also lead to even more serious problems over time.

6.Blockages

Leaving your boiler inactive over the warmer summer months can lead to blockages, which may slow water flow in your heating system and cause cold spots on radiators. If your boiler is making a noise similar to a kettle boiling, this could indicate restricted water flow. Additionally, if the water is dark when bleeding your radiators, it’s likely that sludge has built up in the system and needs to be addressed.

7.Strange smells and noises

If your boiler is starting to give off a bad smell it could be a sign of a carbon monoxide leak, which is extremely dangerous and should be addressed immediately. Banging or clunking sounds are often caused by ‘kettling’, caused by a limescale build up in the heat exchanger. If your boiler seems to be whistling or hissing it could indicate a water pressure issue or a partially closed valve, so don’t ignore tell-tale signs of boiler troubles.

It’s important for homeowners to check their home insurance includes home emergency cover, this normally covers boiler breakdown and repairs – if not, it can be added as an extra or purchased as a separate policy.   As a price comparison site, Quotezone helps homeowners compare and find savings on all sorts of essentials, such as home emergency cover, boiler cover and home insurance. 

References:

*https://landlordknowledge.co.uk/english-households-spend-32m-annually-on-boiler-repairs/
**https://www.landlordvision.co.uk/blog/landlords-guide-boiler-maintenance/#:~:text=The%20Landlord%20and%20Tenant%20Act%20(1985)%20outlines,24%20hours%20of%20a%20problem%20being%20reported

SURVEY – Quotezone.co.uk’s findings are based on a randomised survey of 1,000 respondents across the UK during September 2025, which represents a margin of error of approximately 5% at a 95% confidence level.