Boiler Bang on Startup

[xyberlink]

Hi,

I have a problem with my Ideal Response 120 combi-boiler. When I turn on hot water or the CH comes on the boiler goes through it's startup sequence...

The fans starts up
The gas valve opens
The burner lights

Then within a few seconds there's a loud bang or thump inside. If you take the outer cover off you can see the inner cover move slightly when the bang occurs.

I've been told the problem relates to gas pressure. When the gas value opens, the pressure drops below the minimum 20mbar and thus the gas mix goes all to pot.

Nobody seems to know what is causing the problem. The installation is 5 months old (new house) and worked perfectly for the first 3.5 months.

I've been told numerous times that the regulator on the gas meter is faulty but it been replaced twice and still the problem occurs.

The mains pressure up to the regulator remains at a stable 25mbar. The boiler has been ispected three times by the manufacturer who claim it isn't at fault.

Does anyone have any ideas what may cause this?

Thanks.

 

[sifu]

If you have the correct sized gas supply pipe i.e. 22mm pipe and transco have eliminated the meter governor then the boiler is faulty. These boilers ignite at 10mb. The burner is fully modulating and the pressure is controlled by the speed of the fan. Explosive ignition is dangerous so Ideal should not have even left the boiler on. Ideal had a number of problems with the Ideal Isar combi which was causing severe explosive ignition. After a PCB and ignition lead modification they told the company I work for that the boiler was OK, it wasn't and we continued to experience explosive ignition. We have now stopped fitting the Isar, although they now say all problems have been rectified. Get Ideal back and keep doing so (mention the Isar and ask if it is a related fault >).
If you're lucky it is just a problem with the spark gap and you need a new ignition system. If this turns out to be a common fault I normally find out within 3 months through a technical bulleting. So if you still have the problem, then mention it in these forums again and I may be able to help.


Paul

 

[grolsh]

If you have the correct sized gas supply pipe i.e. 22mm pipe and transco have eliminated the meter governor then the boiler is faulty. These boilers ignite at 10mb. The burner is fully modulating and the pressure is controlled by the speed of the fan. Explosive ignition is dangerous so Ideal should not have even left the boiler on. Ideal had a number of problems with the Ideal Isar combi which was causing severe explosive ignition. After a PCB and ignition lead modification they told the company I work for that the boiler was OK, it wasn't and we continued to experience explosive ignition. We have now stopped fitting the Isar, although they now say all problems have been rectified. Get Ideal back and keep doing so (mention the Isar and ask if it is a related fault >).
If you're lucky it is just a problem with the spark gap and you need a new ignition system. If this turns out to be a common fault I normally find out within 3 months through a technical bulleting. So if you still have the problem, then mention it in these forums again and I may be able to help.


Paul

hi there sifu you mentioned a techcnical bullitin vwhere can i get this technical info from ..........

 

[breezer]

I think the answer to your question is: in order to receive technical bullitens, you should belong to a trade assosiation / be registered with a manufacturing company.

I have worked for several companies that receive technical bullitens, they are not for general public consumption, ususally on the grounds that, you have to be qaulified to carry out and understand what the bulliten refers to.

 

[grolsh]

I think the answer to your question is: in order to receive technical bullitens, you should belong to a trade assosiation / be registered with a manufacturing company.

I have worked for several companies that receive technical bullitens, they are not for general public consumption, ususally on the grounds that, you have to be qaulified to carry out and understand what the bulliten refers to.

breezer i am a corgi registerd gas engineer but would like to know where to get these bullitins from thankyou