back boiler banging noise from pipes

[mondeoglx]

hello we have a baxi back boiler
we no it is old but have it seviced regular to be safe
the boiler works on timer for cental heating and water
last night the boiler went off at 10pm about 11 30 we heard
a banging noise souded as though it was comming through the box where pump is the boiler wasnt on so checked if pilot light was on it was i then bled the raditors one had a lot of air in it after a while the noise stopped
the boiler came on this morning at 5am and went off at 10 am no probs do you think the air in the rad was the problem and why did it take so long after boiler went off to start the noise many thks for you help

 

[Agile]

Either you have a frost stat which brought the system on or an intermittent fault somewhere.

It could have beeen the effect of air in the system or you have a problem.

I suggest you monitor the operating over the next few days including inspecting the F&E tank.

Tony

 

[mondeoglx]

thks for the quick reply how would we no if we have a frost timer also what is the f/e tank and what should we be looking for

 

[gas4you]

I would doubt very much you have a frost stat on this system.

The feed & expansion tank is the small tank in the loft. Check it is full of water.

 

[mondeoglx]

dosnt that fill up off main water tank

 

[gas4you]

No, it should have its own ball valve, although one or two may need manually filling, as the servowarm installations did many years ago.

 

[mondeoglx]

thks will check later