The only way to improve this rating would be to clean the boiler's heat exchanger. To be able to do that would require knowledge of, and possibly parts for this "not so common" boiler.
Damien seemed quite capable and thorough. He even took the time to clean the condensate pump, which was appreciated.
See first remark above. Damien did a fine job with the boiler maintenance.
We felt the immediate benefits of the "clean space' vapor barrier system in the crawl space and...