Gas Boiler Boom On Burner Shutdown

[Blong]

I have a Halstead Hero boiler which sometimes "pops" (converted to a "boom" by the casing) when the burner shuts down. It only happens when the boiler is very hot and seems to be a similar effect to the pop which used to occur on gas hobs when they were turned off.

The burner pressure is spot on and drops to zero immediately when the solenoids release. The specified restrictor is fitted to the flue.

What could cause this?

 

[45yearsagasman]

Thats caused by the remaining gas in the burner lighting back inside.It may also be symptoms of a gas valve passing after shutting down.How do you know the BP is spot on? A simple test with the correct instrument will detect a gas valve thats passing.

 

[Blong]

I measure the burner pressure with a gauge on the test point. Is there another way?

As I say, the pressure drops to zero, but both solenoids are wired in parallel and I am not sure if the test point measures the output from the main valve or the actual pressure at the jet?

I rather suspect that the flue restrictor errs on the side of efficiency and wonder if there would be any problem if I removed it temporarily to see if this makes a difference?

 

[45yearsagasman]

You're obviously not a trained or competant or registered gas engineer to ask such questions.You have no idea what you are doing so stop wasting time as you will get no further DIY gas advice on here.

 

[Blong]

If you do not know, just say so. There is no need to get aggressive.

 

[45yearsagasman]

Touched a nerve eh? Thats not aggressive just the forum rules.I told you what the fault was and if you don't accept that then make your own arrangements.No offence meant.