Banging boiler

[Peakbog]

Hi

I have a Glow worm back boiler which makes banging/ load popping noises when it fires up. A few weeks ago I drained the system and refilled it, adding some cleaner. I flushed it after a few ours of operation and flushed it out with clean water until the water coming out was reasonably clean. I then added some noise reducing agent to the header tank on the final refill. The system then seemed to run reasonably quiet for about a week. Unfortunately it has gone back to how it was.

The banging noise occurs during the period of time that the gas is on and will continue to pop or bang for a few seconds after the gas has gone out.

Any ideas ? Any solutions ? Appreciate any help,

Thanks

P

 

[Geoffgas1]

Air in the system still . Or failed or failing pump

 

[Peakbog]

Thanks Geoffgas1,

some questions

1. How ould air get into the system ? and how do I get rid of it / keep it out ?

2. How ould the pump cause the problem ?

I am interested because I thought it may still be a corrosion issue. Any comments appreciated as it will help me to work out what to tackle first.

P

 

[keego]

Is it a gravity system or fully pumped?

 

[Peakbog]

Hi

It is gravity water heating, pumped CH, why ?

 

[dal5band]

When I treated our old boiler, the de-scaler was left in for a week. I think the boiler de-scaler is gentle acting for fear of causing damage to other parts, so acts very slowlly

 

[keego]

Hi

It is gravity water heating, pumped CH, why ?

Because if it's gravity & it still bangs when it's on HW only, then it wont be your pump.
That's why we like to know these little details, it saves the batteries in our crystal ball.

 

[Peakbog]

Ah, I see.

Well I ran the boiler in hot water only setting (gravity feed only), and it still bangs. So I guess it is not the pump.

I also guess that leaves

1. Air in system - how does it get there and how do I get rid of it
2. Scale, sludge etc.

Any more comments would be appreciated.

Thanks

P