Why Is My Boiler Making Banging Noises?

Banging Noises

Banging noises in boilers are often associated with kettling, which stems from debris or limescale buildup around the heating exchanger. Hard water areas are particularly prone to limescale buildup. If you hear banging or tapping noises from the pipes under the floor, they might be loose and need retightening.

Drone Noises

A drone-like or airplane-taking-off sound coming from your boiler may indicate a faulty pump. A leaking, worn-out, or debris-filled pump can be the cause of this issue.

In such cases, a Gas Safe registered engineer may attempt to repair the pump. If repair is not feasible, they might recommend replacing the pump, which typically costs between £200 and £300, including installation. Alternatively, if the boiler is over ten years old and not performing well, the engineer might suggest a boiler replacement.

Humming Noises

If your boiler emits a low humming sound, several factors may be at play. High boiler pressure is one common cause, which can be easily checked by looking at the pressure gauge. If the pressure is too high, it can be lowered by bleeding the radiators.

Another reason for a humming boiler could be a circulating pump set too high or fast. This problem can be resolved by adjusting the pump speed.

In some cases, the humming noise might be attributed to a loose or faulty component inside the boiler. In such instances, it’s best to contact a Gas Safe registered engineer to inspect and repair the internal components.

Vibrating Noises

Loose brackets can cause vibrations, and if that’s the case, you can easily tighten them yourself. Another potential cause could be a blocked exterior flue, which can be checked and cleared safely from outside.

However, vibrating noises might also be an indication of sludge buildup within the system or a shaking pump inside the boiler. Both of these issues require professional intervention. An engineer can inspect the boiler, fix the shaking pump, or perform a thorough system cleanse to remove the sludge.

Gurgling Noises

Gurgling noises are quite common in boilers, but constant or loud gurgles can indicate trapped air in the system. To address this, bleeding the radiators is a simple and effective solution. A registered engineer can assist you with this or you could do it yourself.

Incorrect water pressure or a frozen condensate pipe may also be causing the gurgling noises. You can check the pressure gauge to see if it’s too low or high and re-pressurise the system following the user manual instructions. For frozen condensate pipes, use safe methods like a hot water bottle or microwavable heat pack to thaw the blockage.

Kettle Noises (Boiler Kettling)

A boiler producing kettle-like noises is often experiencing a problem known as boiler kettling. This is a common issue that arises due to the buildup of debris or limescale in the system, leading the boiler to overheat and generate steam.

To resolve this problem, the central heating system needs a deep clean. This process, known as powerflushing, involves the use of various chemicals to clear debris and limescale by a professional engineer.

Do not try and do any DIY measures that you are not comfortable with or trained for. While bleeding your radiators can be done yourself, you should not attempt things like powerflushing. Always contact an experienced professional.