This boiler is a Burnham commercial boiler put in on Stratford in Cleveland Hts. It is a high fire/low fire boiler. The steam system is a Mouat vapor system. We have this house heating with just one ounce of pressure at the boiler. We think Tom Mouat would be proud of that. There was no main vent on the end of the long main, so we added a crossover trap as the main vent.