I recently bought a newly remodeled 1950's era house about two months ago. It has a Weil Mclain fuel oil boiler that provides heat to four different zones (loops) in the house. Each zone has a couple of new radiators (the style that mount to the wall and run the whole distance of the wall).
A gas/oil boiler has no inventory or bed of fuel. When you trip the burner for all practical purposes the heat input immediately stops. ... Safety valve lifting; Large sudden change in steam load . ... If one starts to fire the from a cold start the water will up