Banging Boiler

[mgst170]

I have read all the similar posts on this subject, however I can't find a resolution.

I have a Halstead Best boiler, approx 2 years old. When the system heats up, there are loud banging noises made by the boiler. It gets to the point where it sounds like the boiler is going to fall off the wall.

I have tried to descale the system by using chemical additives, and I have also added an automatic bleed valve to the vent pipe at the hot water tank. The boiler temperature is only running at position 3 out of 7 so I can't see the water overheating.

The noises occur when either the CH or HW are on, although it is noisier when the CH is on. The pump is running and circulating the water when these noises occur.

I'm stuck, and any thoughts would be greatly appreciated.
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Moderator

Moved as originally posted in WRONG FORUM (general diy)

 

[oilman]

Powerflushing will help. This uses an acid descaler, and is more effective than the on-line chemicals.

 

[moderator]

Perhaps you can help us. you said

I have read all the similar posts on this subject, however I can't find a resolution.

so why did you post in wrong forum?

 

[kevplumb]

to give the moderator something to do perhaps?

 

[ChrisR]

Do the pipes go UP from the boiler, or down the wall? It sounds like air trapped, at 2 years old...

 

[mgst170]

Mods - Sorry - Will pay more attention next time.

ChrisR - The pipes come in from the ceiling and from the floor.

I does sound like trapped air, but how can I get it out of the boiler?

Thanks again.[/quote]

 

[ChrisR]

SHort answer - air bleed points! Usually air collects in the first radiator, or goes up the vent pipe in a vented system. Is the system sealed or vented? (Pressure guage, or small tank in loft).
Looj at the pipe runs. SOmetmes they get partial (or full!) blockages in crucial bits.
Is there a bleed point by the hot water cylinder?

 

[croydoncorgi]

In the meantime - don't let it bang!
It'll do the boiler no good at all.

 

[mgst170]

It's a vented system.

I've put an automatic bleed at the vent next to the hot water cylinder to try and get any air that might be leaking in.

I've tried to empty & re fill the system, and the automatic bleed works fine as I can hear the air whistling out of it as it fills up.

I take it power flushing is supposed to remove these blockages?

The boiler has been banging for about 6 months now! (as it's been summer, it's not has that much use).

Thanks again.