Remeha avant a plus booming noise on startup

[Kayvee]

Hi everyone.
I know this topic has been up before (c2010) but it doesn't seem to have been solved and I wondered if anyone has had the same thing and fixed it.
It may well be common only to the Remeha Avanta combination boilers so perhaps is a little obscure. My main concern is that this phenomena (booming on ignition) will one day cause an explosion that could cause harm and/or damage.
Because of its intermittent nature the cause of the 'Booming' has evaded all that have attempted a repair, both the manufacturers agents and other gas safe engineers.
If I could afford it I would rip the damn thing off the wall and throw it as far as I could.
It did happen once when the front panel was off and you could see the gas valve actually shake and vibrate, it's a bit scary, it really booms loud!
The whole episode will only last a second or two, as long as it takes to fire up. My own instinct is that unburnt flu gas residual somehow throws off the correct air/full ratio and incorrect initial combustion occurs, But How? The flue is oem and fitted correctly!
Any body fixed this problem please?
Thanks.

 

[Gasguru]

What flue configuration is it...vertical by any chance?

 

[Kayvee]

Hi gas guru, thanks for your interest.
Yes, it is vertical, is this significant?

 

[Gasguru]

You need to check the following with the engineers that have looked at it so far....

The rope seal on the burner has been replaced with the graphite one (the rope seal burns away)

The outer round O ring is correctly fitted on the gas/air manifold

The electrodes are in good condition

The traps not blocked

Combustion correctly setup

Heat exchanger clean

Flue assembled correctly

Ignition spark ok

Gas working pressure ok

Burner insulation panel in good condition

If these are ok then there is one tweak to the settings that may cure it. I've got a customer that had explosive ignition. After the parameter was changed the fault almost disappeared. Very occasionally it will still do it.

Since the parameter change is to do with a critical part of the ignition it's not for broadcast on the open forum.

Message me with your email address.

 

[Kayvee]

It's [email protected]
Thanks again.