My father has a Lennox Duraglass G11 warm air heating boiler and occasionally when it ignites it makes a massive boom. I thought he was exaggerating til I heard how bad it was. He has had an engineer around but it has never been solved. Any ideas??
Had similar problem with a Lennox Unit. Fault was caused by delayed ignition where the main gas was not getting to the constant pilot quick enough and causing a build up. Finally modjfied the unit by relocating the pilot assembly into the centre of the main burner bar. No explosions since.
The modification is quite simple. If your engineer buys a 6mm Bundy kit,
which comprises of a length of 6mm soft alloy pipe and a selection of fittings, it is then a matter of re-location of the pilot assembly with a couple of screws and repipe back to the gas valve. GSR engineer is a must.