im having a real problem with my boiler, the ignition flame would not stay alight few months ago so called corgi engineer to come out he checked it cleaned some parts and it was working fine now the problem is somewhat different the boiler fires up but when it fires up wind blows the flame out? engineer says its backdraft or something even he cannot figure it out?boiler is placed with vent directly behind it outside. dont know what to do costing me a fortune!!!never had this problem until engineer fixed boiler for pilot not staying alight, lived here for 2years only recently started happening but getting worse?only stays on for about 5mins and cuts out, you can the flame blowing through the little window on the boiler.............HELPPPPPPPPP!!!