A loud banging noise
coming out of a boiler is surely a matter of concern. Anyone in that case would
wonder as to why the boiler makes banging noise when firing up. Well, there can
be two reasons to this-
- If your boiler makes a single BANG only when it
fires up, it’s most likely due to delayed ignition- The problem of delayed ignition is quite commonly
found in gas boilers that use pilot lights in contrast to the electronic
ignition systems. When a gas boiler receives the call for heat, the gas valve
opens and releases a small amount of gas into a sealed combustion chamber through
small “jets”. This gas then gets ignited by the pilot light and the jet flames
heat up the heat exchanger. Delayed ignition
occurs when the gas that is sent into the combustion chamber doesn’t immediately
ignite. And when that happens, the
gas builds and builds inside the combustion chamber until bang, creating a mini
- Problems causing Delayed Ignition
- Not enough gas
- Not enough surrounding
- Dirty burners
- A bad gas pilot
- What can we do about it?
case of a delayed ignition, we would highly recommend you to fall for the
professional help, as the intensity of the flames caused by the gas buildup can
eventually cause your boiler’s heat exchanger to crack, which might let out the
carbon monoxide gas off the combustion chamber, resulting into carbon monoxide
poisoning which can be very harmful.
- If your boiler
makes recurring banging, popping noises as it operates, it’s most likely due to
“kettling”- Kettling is something which
occurs as a result of the lime scale buildup in the system that eventually
creates bubbles and leads to the occurrence of ‘hot spots’. These hot spots are what causes loud noise
and needs to be treated with a solution in order to clear the lime scale
blockage. However there are a number of other reasons as well that can cause
- Problems that cause kettling
- Lime scale deposits on the heat exchanger
- Water pressure/flow is too low- When the water flow is too low, water runs over the
heat exchanger much slower than it should. This slower pace causes the water to
overheat, thus giving rise to steam bubbles which erupt forcefully when they
reach cooler water.
- Bad thermostat-If
you have a faulty boiler thermostat, it would allow the burners to stay on
longer than it should thus causing the heat exchanger to overheat. Therefore,
when water comes into contact with the extremely hot heat exchanger, steam
bubbles are created, which then erupt noisily.
- Water temperature on boiler is set too high- Setting your boiler to a very high temperature can
overheat the water, causing steam bubbles and eventually resulting into a
- What can we do about it?
this case you could either bleed your system or repressurise it. However, we
would recommend you to consult a professional help regarding the same in order
to avoid any danger to self.