Boiler not igniting? Common issues and how to fix them
It can be easy to panic when your boiler turns off and can’t reignite, as this leads to a complete loss of heating and hot water. Maybe you’ve come back from holiday only to return to a house that can’t be warmed up, or it simply happens out of the blue during a period of extreme cold. Don’t worry, there are many possible explanations for a boiler that won’t ignite. Below we’ll be covering the common issues associated with this problem, as well as how they can be fixed.
What can cause my boiler not to ignite?
Most boilers can be ignited by pushing the reset button on the unit and holding it down for a period of time. The boiler should then ignite after a few minutes. Its user/manufacturer manual may also provide instructions for resetting that particular model. When this process is followed without resulting in boiler ignition, there is likely a fault causing the issue. A failed boiler ignition can be caused by a variety of factors, the most common of which are listed here:
There are many different electrical components within a boiler that are responsible for monitoring certain things and triggering certain processes. For instance, faulty wiring or a defective part of the printed control board (PCB) can cause the boiler to fail to ignite when the sequence has been triggered. Other electrical issues can arise from a loss of power throughout the building, or a localised loss of power due to a tripped fuse.
Gas boilers have a pilot light that acts as a small heat source that lights the gas provided by the main burner. The jet that feeds fuel to the pilot light is usually very small in diameter and so it can be easily blocked by debris within the system. The pilot light can go out due to a blockage in the burner, which itself can lead to a lack of boiler ignition.
When the boiler gas valve fails, either because it has become jammed or blocked, gas can no longer flow into the burner. This can cause the unit to fail to ignite.
Frozen water in the pipes can cause a blockage that prevents circulation within the boiler. Even the smallest amount of frozen water can prevent ignition from occurring.
The boiler fan is an essential component as it is responsible for the extraction of combustion gases from the system. If the fan stops working as it should, the boiler will shut off and won’t ignite as a safety mechanism.
Finally, your boiler might not be igniting simply because the inputted temperature has been reached in the property. As such, the boiler won’t come on in order to save fuel.
Fixes for a boiler that isn’t igniting
There are many options for fixing a boiler that won’t ignite. However, each of these fixes depends on the cause of the problem. These are as follows:
- For electrical issues – first check the fuse box to confirm that no fuses have been tripped which might cause ignition failure. If the boiler cannot be reignited after power has been restored to all parts of the building, it will be necessary to call a gas safe engineer to investigate. They may need to source specific boiler electrical parts to carry out repairs, such as a boiler electrode replacement.
- For pilot light issues – the jet that feeds the boiler pilot light will have to be cleaned or replaced, depending on the severity of the problem.
- For gas valve issues – an engineer will have to locate why the gas valve isn’t closing. If it’s due to a blockage, this will need to be cleaned. However, a damaged or defective valve will need to be replaced with an appropriate new or refurbished part.
- For frozen pipes – thawing frozen pipes can take time depending on the environment and the location of the pipe. For instance, the boiler flue pipe is more prone to freezing as much of it is exposed to the elements.
- For temperature issues – simply set the boiler temperature to be higher than what it was previously set to. This can be done as a way to rule out this issue, as if the boiler doesn’t ignite after the temperature has been adjusted there may be another issue causing the ignition to fail.
Gas boiler spare parts with next day delivery
National Boiler Spares offers a quick and easy service for engineers and homeowners looking to source cost effective boiler parts and spares. We understand that a boiler that won’t ignite is a serious problem that has to be fixed at short notice, which is why we offer next day delivery depending on when you put an order in. We stock replacement parts for a wide range of makes, models, and brands. This includes the likes of Ideal, Veissmann, Vaillant, Worcester, and Baxi, to name just a few. Whatever the nature of your issue is, don’t hesitate to contact us to find out exactly which of our services can best suit your needs.