Loud banging in central heating system

[Malharley]

Hi there,
I get a real loud banging in my central heating system on average once a day that seems to start with a wooshing noise at the boiler then radiates out rattling all the pipes around the house. After a few seconds it seems to sort itself out then its alright again. The wooshing noise I think is water being forced extra fast through the boiler. Does anyone have any idea what is causing this to happen? The system is about 15 years old and the boiler is a Mysen Appolo. Would really appreciate any advice anyone can give me.

 

[garagerob]

its most likely to be air in your system, try bleeding your radiators while the heating is off.

 

[pipeslice]

Tell me is it a combi !!!

Mine does it every time on start up/burns bangs boils prv open discharge fill it up cause it`s empty then it`s grand

 

[Softus]

Which ****ing boiler?

 

[twgas]

try switching boiler stat to low, if that stops the noise you need a new Hi stat.

 

[Malharley]

Many thanks for all your ideas. Very much appreciated.

Garagerob, I have bled all the rads and hardly any air came out but problem still persists.

Pipeslice, No its not a combi, just an open vented boiler

Softus, so I got the spelling wrong! Should be Mysen Apollo

TWgas, thanks for the tip, however did not fix problem but was worth a try

 

[namsag]

Loud banging on an apollo is usually asociated with the pump stopping , which can be caused by the pump over run stat not returning to it proper postion after a call for heat,
Then when either CH OR hw call for heat again the burner fires up but the pump does not start (so loud banging as water expands and trys to get away) untill the pump over run stat senses heat within the combustion chamber and switches to give power to the pump again then everything runs quiet and normal

 

[Softus]

Softus, so I got the spelling wrong! Should be Mysen Apollo

That mumbling sound is me trying to eat humble pie with egg on my face.

I hereby tender my sincerest apologies for not reading your initial post properly.

 

[Malharley]

Thanks for your advice Namsag. Sounds like you've got the answer there. Now when I call the service engineer out he won't be able to fob me off saying that "its nothing" and leaving it. Many thanks