Lockout after 11 years can you help with some ideas?

I have a Thermecon External wall mounted boiler that is 11 years old. Other than cleaning and servicing, I have never had any problem with this unit and it has been used year round for heating and hot water. Today we returned from a 7 day break to find it out of action with a lockout. I have taken the blower assy. out and cleaned it,(it was a little sooted up around the hot end), there were no leaks, but found what appears to be an arc on the bottom seal of the coil.
Don't know if this is the cause, because there are no heavy fuel vapors although the tiger loop is still primed, and the pump feels like it is operating ok. Could I have a vapour lock? I haven't broken any lines to see if I have fuel flow.
My usual servicing technician has refused the job. I think his gravey years of servicing it are over.
Also, I would like to know if you think it would be wise to buy a new blower unit rather than to just start fixing things now as they start to go wrong. The framwork and casting are in good order too. maybe I culd get another 11 years of troublefree service that way. Also, where would be the best source of parts?