Boiler making very loud noise, help

If your boiler makes a single BANG when it fires up… the problem is most likely delayed ignition. Delayed ignition is a problem that’s common in gas boilers that use pilot lights (as opposed to electronic ignition systems). If your boiler makes recurring banging, popping noises as it operates… ...the problem is most likely “kettling”. Kettling can happen in any kind of boiler. It essentially means that your boiler’s heat exchanger (the part that actually heats the water) is too hot. When this happens, water that comes into direct contact with the heat exchangers gives rise to tiny steam bubbles. As soon as those bubbles drift away from the heat exchanger into cooler water, they burst—creating that persistent banging/popping noise you hear. Best thing to do is get a Gas Safe Registerd Heating Engineer to have a look.

Boiler is having circulation problem, there seems to be blockage in the system.

I believe it to be the expansion vessel and or possibly a blockage/scaled up heat ex.

If its a combination boiler it be pump? Expansion vessel, is it losing pressure over time?

If you experience a problem with your boilers please get in touch and we can help you out. Please do not attempt to fix your own boilers as it is only for qualified gas safe engineers.

I would suggest that there is a severe build up of sludge or iron oxide in the heating system. It needs a chemical flush and possibly, depending on how old the heating system is, a power flush. & a magnetic heating filter installed This normally takes up to a day

A blocked Plate h/e , pump , exp vessel . Have you got the hw preheat on if it is coming on a night ?