Strange boiler sounds

[Julian]

The patient is a floor standing, balanced flue, bog standard, LPG fired Ideal Standard Mexico.

Yesterday, when it lit up, it started making quite a loud 'roaring' sound, (it normally makes very little sound) I looked through the little glass window and it appeared that one of the burner units had partially lit up actually inside the casing. I switched it off then on again and all has been normal since.Today I removed the burners and hoovered them clean - they were pretty clean anyway because it had been done only a month or so ago.

I'm wondering what makes this happen, is it a worry, and what must I do to prevent it again? Any BTDT/tips much appreciated

TIA Julian.

[Ed Sirett]

There are lots of ways a gas burner can go wrong although they mostly don't.

Does the flame ignite of the whole burner easily? What was the colour of the flames?

[Julian]

Yes, it lookes like it does, both burner 'blocks' seem just the same.

Well at the time one burner block was giving a yellowish flame, the other nice and blue. (like a blowtorch) But after I switched the burners off and on again they both became nice and blue. It's been running fine since, no problems whatsoever - I'll be waiting to see if it does it again.

Can I buy new burner blocks? Or maybe the little brass gas nozzles - although I can't see them wearing out.

Julian.

[Ed Sirett]

My guess is that the flame jumped back to one of the injectors this is really bad news. If left for any amount of time the whole burner would rapidly fill with soot.

There are probably several ways for this to happen but the only one I have seen is due to the gas valve not shutting off 100%.

If you can competently measure the gas tightness of the installation and service the burner then do so otherwise get in professional help, asap.

[Julian]

Thanks for the reply. The thing is in the kitchen (where we tend to live) so I can monitor it pretty much most of the time and it's been perfectly behaved since. I wonder if a freak gust of wind blew up the flue and disturbed the flames? I cant measure gas tightness, but have serviced (cleaned) the burner unit. I'll see how it goes for a while. I think the thing is about 10 years old now, but the burner assembly looks almost like new when all the crap from the cast iron heat exchanger has been Hoovered off!

We've only been in this house a few months, and the gas boiler is pretty new to me. My old house had a pressure jet oil burner boiler and I knew everything about that and could fix it in a jiffy!

Cheers Julian.