Our original low pressure Coal Fired Steam Boiler has been replaced by a Natural Gas Boiler; what should our system operating pressure be?
Generally speaking, an old ‘nothing fancy’ gravity return system was able to operate comfortably at 2psi (or less) pressure. Provided all other equipment is in working order with properly maintained Steam Traps, and barring other unforeseen problems such as the modern boiler holding too little water, the system can still operate well at a low pressure. In fact, the lower the operating pressure is, the better. Boiler standard Pressuretrols can be replaced with a Vaporstat to achieve consistently lower pressure, and greater pressure sensitivity. We have many years of experience working with contractors who installed Vaporstats, and witnessed numerous homes that have been heated comfortably at 2 to 16 oz. pressures.
