The winter period is a busy time for installers and it’s also the time where most boiler problems occur for homeowners. Here product manager, Phil Birchenough, discusses the most common boiler problems and how minor problems can be fixed at home.

Many homeowners wouldn’t know what to do if a problem occurred with their boiler. Therefore, people aren’t aware that many minor issues can be solved without the help of an installer.

That said, as it is a gas appliance, it’s vital that the appropriate care is taken, so if you don’t feel confident in fixing a problem yourself, we would always recommend getting advice from a Gas-Safe registered installer.

Some of the most common boiler problems are:

  1. Low pressure
    Low pressure is a common boiler issue and this is often the cause of a boiler not working. The pressure gauge will be able to tell you if the pressure is low and if it is, it’s easily fixable. Your manual will be able to give you step-by-step instructions on how to top up the pressure. Most boilers will automatically reset and the error code will disappear once you have done this.
  2. Air in the system
    Air in your system can cause your radiators to stop working. If you turn your heating on for the first time in months and find that your radiators aren’t getting hot then this could mean that your radiators need bleeding. Bleeding your radiator is simple – all you need to do is remove the valve on the side of your radiator to let out the trapped air. Make sure the heating is off when you do this. You may also want to have a bowl ready in case any water escapes. Remember, bleeding your radiators can also lead to low pressure. Be sure to check the pressure in your system (as above) once you have bled them.
  3. Error codes
    Having an error code flash up on your boiler can be scary, but most of the time it’s easily dealt with. If an error code appears, your manual will usually be able to tell you what it means and how to rectify the issue. For instance, if you have a pre-payment meter you may run out of gas, this will cause a fault code to appear. Once the gas supply has been reinstated you will then need to press the reset button on the boiler. However, if you are still unsure about what to do, an installer would be able to give you advice over the phone. Contacting your boiler manufacturer is also an option. Most manufacturer websites will have an error code explanation. If you have a Sime boiler, you can view our error code guide on our website.
  4. Frozen condensate pipe
    Snow and ice can cause your pipes to freeze over causing your boiler to stop working. If your boiler turns off during low temperatures, checking your outside pipe could indicate your problem. If your pipe is frozen and it is easy to access, you can defrost it yourself using warm water. You can read more about this in our blog about frozen condensate pipes.
    If you need the help of an installer but can’t get an appointment, researching the problem online could also help you understand what the issue is and if you can resolve it yourself. You can find the HHIC guide to frozen condensate pipes on our website.

Many people use social media or visit online chat forums to speak to other people who may have had a similar problem. YouTube can also be a useful tool. Alternatively, even if they can’t visit you face-to-face, your installer might be able to give you advice over the phone.

Also, having your boiler serviced annually will help to ensure your boiler remains in good working order and will hopefully prevent major issues from happening.

Even though minor problems can be solved without professional help, it is also important to take care when dealing with your boiler.

If you have a question about your Sime boiler or would like some advice, you can contact our customer services team on 0345 901 1114 or by emailing