Loud banging from airing cupboard when heating is on

[kncowans]

Hello

I hope someone can help me with this problem as it is starting to really annoy us.

The boiler is a Maxol HomeWarm 600.

I leave the heating turned on at the timer in the airing cupboard and control the heating with the thermostat situated in the hall.

After the heating has been on for a few hours (this is not constant) at approximately 20 Degrees C there is a very loud banging that sounds as if it is coming from the airing cupboard.

There is also a kind of crunching sound that comes from the radiators even though they are warm.

If I run the hot water tap for a few seconds then the banging will stop.

The only other option is to turn the heating off but this is obviously not ideal.

I have tried bleeding the radiators using the key but there is no air in any of them.

I have had British Gas out previously but the banging never happens whilst they are here (typical) and everything they have checked has been fine.

The pump has even been replaced just incase but the problem still exists.

Anyone have any suggestions?

Thanks in advance for any help you can provide.

Kevin

[The Heating Doctor]

Is your cylinder thermostat working as the noise could be down to the fact that the water in the cylinder is boiling. When you run a tap, this introduces cold water in to the cylinder which stops the boiling.

[kncowans]

Hello

Thanks for the reply.

The cylinder thermostat has been checked and is working fine.

Thanks in advance

Kevin