hi i have a problem with my combi boiler, its a Halstead finest gold. its about 9 years old and has been very reliable up to just recently. the problem is with the front cover removed not just the white cover but the one that covers the burner it operates fine but with the cover on the red lockout light comes on after a minute or so. the fan was noisy so i took it out and cleaned it and a bit of wd40 fixed the dry bearing so all the fan and the flue is clear.to me it seems like it could be an overheat problem?. any ideas any info gratefully received. thanks. 
