"Explosion ignition" and high bar pressure during use.

[kinlungchan]

System Saunier Duval System 400 (25 year old combi boiler)

Boiler has been making a loud thudding whoosh sound which rattles the case when firing back up during normal use. I think they call it "explosive ignition"

The Boiler was serviced by British Gas a few days ago. He told me this was normal. I think the feriocity of the whoosh and rattling of internals has increased since he balanced the radiators. More heat from all 12 radiators and better running system.

The boiler pressure in bars goes from 1 to 4. It's just below 1 before turning on and slowly creeps up to just under 3 in about a hours time of use. Is this normal?

Again the British Gas engineers said the system was fine and signed off the service.
My knowledge and understanding has come from using google over last few days (i'am by no means an expert) and the same things terms & answers seem to come up.

ie you shouldn't see a big increase in pressure during use, explosive ignition problem is not normal and needs checking. The filling loop needs to be disconnected. And loss of charge/pressure in expansion vessel can cause rise in pressure.

Does anyone see a pattern here? I would like to call a local engineer to fault find this and would like some background knowlegde to ask questions.

Thanks in advance Tony.

[Toddyplumb]

You need to get BG back if you are having problems

[kinlungchan]

I've spoke to my friends and they tell me their boilers are noisy to some extent. The main concern is the boiler pressure. From the information i've read on the Internet this seems to be the priority.... Thanks for the advice.

[gasmarc]

what you need to do is utube it ,your boiler could have a worn burner or maybe set up incorrectly . get BG out and dont let them leave until its fixed and dont take that rubbish that bits are unavailable ,good luck give them a call today before 1 and they guarantee to be out that afternoon

[kinlungchan]

Cheers sound advice there. Never thought of looking on Youtube :-)

[gasmarc]

what I was hoping you could film your boilers fault and put it on utube for us all to see please

[kinlungchan]

Ahh. So many uses for youtube these days.... once a source of online you've been framed videos, now education and world news.

Here you go...

YouTube - noisy boiler.mov.MOV

[kinlungchan]

BG engineer has been. Spent a hour cleaning more parts. Says the gas levels and ignition parts visually look fine. He will return tomorrow with new gas pilot/valve/tube parts for the process of elimination....

[gasmarc]

excellent news you need to get that sorted so there is no noise or very little obviously the first engineer was talking out his back side ,you may need a new burner which as i have said they might try and fob you off saying you need a new boiler, hopefully not

[kinlungchan]

it was the same engineer lol he wanted to fob me off saying it was normal noises... when he listened to it properly he changed his mind and spent a hour and half fault finding. He's back today and hopefully will continue the mission with excitement and pride....

[kinlungchan]

New ignition system installed. A click before the gas fires back up and silence. Operating for 2hrs and no loud clatter. Can't believe how quite the operating noise is...

Good thing about the internet and forums like this is that you can push the Engineer to fix problems... with some basic understanding and examples.

This engineer was a good lad though his enthusiasm to investigate the problem wasn't there at the start but he did prevail. Maybe British Gas aren't that bad hahah

Also no extra cost for time fixing and component. This was a continuation of a paid 'service' to the boiler.

Cheers for feedback 'gasmarc' :-)

[plumberdarren]

get him to check the charge in the expansion vessel when he comes back 1 bar static to 3bar when hot is quite alot.

[gasmarc]

no problem ,if BG are advertising this great service avail of it if you want to save a fortune further down the like , I agree with plumberdarren and also ask him to check the automatic air vent has no signs of leaks and is not weeping, good luck

[kinlungchan]

It's now reading just over 2 bar after 5hrs in operation.

It was £50 for a one of service, it just so happens that i mentioned the increase in noise after the service.

I'm guessing they usually charge for the extra time and cost of components but this guy was a goody :-)

So far so good. *Touch wood*