My Boiler is Making Banging Noises

You have every right to be worried if your boiler has banging noises. In most cases, you must be worried if the problem is dangerous and what could happen.

Banging or popping noises from your boiler is not a normal phenomenon. If you notice such sounds, it is important that you get in touch with our professionals at 2 RED to come and examine the system.

To help you understand your boiler better, there are two main reasons why your boiler could be making the loud banging noises.

Delayed Ignition

There are two types of banging noises that can come from your boiler. The first is when the boiler is firing up. It happens only once and after the boiler has fired up, there are no more noises. This is usually associated with gas boilers and happens as a result of delayed ignition.

During ignition in gas boilers, a small amount of gas is injected into the combustion chamber, the gas is then ignited by pilot lights. When the boiler has a problem igniting, the gas injected into the combustion chamber accumulates. Once the pilot light ignites the gas, there is a mini explosion in the chamber. This is the banging noise you hear.

If your boiler has delayed ignition, get in touch with us today. We will send a technician to your location to identify the problem that is causing the delay in ignition.


The second and more concerning type of banging in boilers is recurrent. It is as a result of Kettling. In this case, the banging noise might also be accompanied by popping sounds.

Unlike in the case of delayed ignition which affects gas boilers, Kettling affects all kinds of boilers. Kettling happens when the heat exchanger in your boiler gets too hot. When the water touches the exchanger, bubbles rise and drift into cooler where they burst and create the popping sounds you hear.

Kettling is caused by a variety of factors. The most common is limescale which is common in areas with hard water. The limescale layer builds on the heat exchanger. It creates a barrier between the water and the exchanger. This makes water flow slower and the burner stays on longer.

Kettling can also be caused by low water pressure. If the water is flowing slower than it should, the burner gets hotter. Other factors include a bad thermostat or setting the water temperature too high on the boiler.

See similar post: Water Dripping from the Boiler

What should you do

Whether the banging happens during startup or it is recurrent, it is important that you have a professional look at your boiler. 2 RED offers a variety of services that can help solve any problems with your boiler including the banging.

Give us a call today and we will have a qualified technician at your door ready to assess your boiler and provide you with the most practical and lasting solution. It is important that the banging is addressed as soon as possible to prevent further damage and more costly repairs.

Write a Comment