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There is never a good time for boilers to go wrong. So it is essential to know what to expect could go wrong so that you are on the front foot.

  1. Boiler error codes
  2. Boilers leaking water
  3. Noisy boilers
  4. The boiler is working but no heating
  5. Condensing boiler problems
  6. Boiler not turning on
  7. Low boiler pressure symptoms
  8. Boiler not responding to thermostat
  9. Boiler not firing up for hot water
  10. Central heating problems

Signs & causes of boiler problems

Boiler fault codes

Many different fault codes vary with boiler manufacturer and models, so the first step is to look up your fault code in the manual, Herofix’s guides or the internet to learn the meaning of it.

Leaking boilers

Water dropping from below your boiler can be from a pipe below, which could be an easy fix or one for a plumber. If the leak is coming from inside the boiler behind the case, then it is a job for a Gas Safe engineer.

Noisy boilers

Lots of different noises can come from your boiler. Although, most common noises are related to blockages resulting in banging noises. The blockages are likely from sludge in your system, which is mostly made up of corrosion of your radiators. A system flush is the best course of action.

Hot water is working but heating not or heating is working but hot water not

Motorised valves, thermostats, diverter valves, and pumps are often the culprits here. Most likely one for a professional to investigate which control is at fault, as there is a sequence to follow to diagnose the problem.

No power at your boiler

If there are no lights or displays at your boiler, then check your controls to see if there is power there. The issue could be a blown main fuse in the spur, which is easy to change, or something could have tripped the power completely. A process of elimination.

Low boiler pressure

Sealed systems require there to be pressure in the system. Cold radiators or no hot water is often the first sign that the pressure has dropped. Topping the pressure back up should be straightforward once you know how to. There should be some valves which you can turn on and off to allow water back into the system to raise the pressure again. Persistent low boiler pressure needs further investigation though.

Troubleshooting your common boiler problems

Some handy troubleshooting tips can include:

  • Looking for leaks: Trace upwards to find the source of the leak. Also, using tissue to soak up the water will help indicate if something is leaking and where.
  • Keeping records of when leaks or noises happen, like using hot water or radiators at the time. Monitoring can give key information to a qualified professional, which saves you time and money.
  • Diagnosing boiler error codes: These will be in the manufacturer’s literature given to you when your boiler was installed. They can be found all over the internet and at
  • Check the boiler pressure: Low boiler pressure is a common cause for many central heating and hot water problems, so make that your first port of call.
  • Resetting your boiler: To reset your boiler, it will vary between manufacturers and models. Although, they can all be reset even if it means turning the power off at the main spur for 10 seconds and back on again.
  • Bleeding your radiators: Keeping air out of your radiators lower the chance of air getting into your boiler.
  • Book a video call at with a professional – it’s an experienced plumbers job to troubleshoot and find faults, so if you’re unsure of anything, guidance from a pro will quickly help you find the source of the problem.

7 tips to maintain your boiler

1. Protecting your boiler: Inhibitor!

The hint is in the name. The chemical wants to stop your system from corroding which will help you avoid blockages, leaks, and inefficiently running systems, boiler breakdowns and unexpected costly repair works.

2. A clean system is a happy system

Having your system power flushed every 5 years is good to practise if you have an older gravity system. Sealed systems are not as bad for rusting so you will get away with slightly less regularly.

3. Annual boiler service

All gas and oil boilers should be serviced annually to be checked for proper functioning and at this time it is possible for a qualified engineer to spot any obvious problems approaching, so you can be proactive in staying ahead of any unwanted breakdowns.

4. Balanced system

If your radiators are balanced then your boiler will be able to work less hard in producing the heat to be sent around the system so it will not need to be running for as long periods.

5. Thermostatic radiator valves

These valves give you the control to make some rooms cooler than others, enabling the boiler to do less of a job once the cooler rooms have reached temperature. The less time the boiler is burning the easier the boilers job, and the longer it should last.

6. Room thermostat and programmer

Similar to above, the room thermostat should be set to a comfortable temperature (not too hot) and the times set to when you need it on and not when it is unnecessary. So once again, the boiler is only running as much as it needs to. Smart thermostats are the best option and some of them can even learn your living patterns making your system super economical.

7. Boiler guarantees

Unfortunately, they don’t make things like they used to, whether it is your tv, car, washing machine and sorry to say but your boiler too. The best thing you can do is to get a boiler with a long guarantee and many of them come with 10 years or more now. Also, check how good the guarantee is, some only offer a warranty which is not as good as a guarantee. In our opinion, Worcester Bosch offers the best guarantee as they look after their customers most loyally when it comes to repairing one of their broken down boilers.


To sum it up, if you look after your boiler and central heating system, it will look after you. There are things to do annually, periodically during the boilers life and when purchasing a boiler to make sure the boiler will last as long as possible and not struggle. Also, acting as swiftly as possible when an issue arises is the best way to avoid something escalating to a bigger problem.

The quickest and most convenient option is to book a 15-minute video call at Here, you will learn how to fix something yourself, giving you skills and knowledge to take away for life; or you could have the problem diagnosed at the fraction of the cost of a heating engineers call-out fee, saving you lots of money to spend on more fun things.