Boiler banging noises when refilling system

[sha256]

Yesterday I drained down the my CH, soldered on some new joints and fitted in a new rad. All went swimmingly. When I filled the system, put in inhibitor, cleared the rads of air and started the boiler, it made some banging noises for about a minute or two whenever the flame light would turn on. Then the reset button started to flash and I had to reset the boiler. The boiler is working fine now.

Does anyone know what caused the banging noises ? And why the reset button started to flash ? I have a worchester 24i installed in 2012.

 

[dcawkwell]

Air in the heat exchanger.

I always run a boiler with the gas switched off a couple of times
until the boiler locks out but has a chance the clear the air out.

A burner can rapidly damage modern heat exchangers when they
have air trapped in them.

 

[sha256]

thanks. How can I remove the air ? Its been afew days, whenever the heating it on the banging noise is not present. However, turn the heating off and it starts to make the noise everytime the flame light comes on.