Best Of

Don’t dismiss the fine points of dialing in your steam heat’s operation. I’ll add to the consensus that Getting control of the pressure and assuring you have good venting is really where big savings can be had. I would add that you should confirm the boiler is piped to the instructions provided with the boiler (at minimum) and that it was properly skimmed when installed. The latter two points are important for production of “dry” steam. Dry Steam carries few water droplets with it, providing maximum efficiency in heat transfer. Wet steam is heavy and wastes energy.

Regarding target pressure, it might be worthwhile to understand what variety of steam system you have. The reason I mention this is that if yours is a two pipe vapor system and you’re running more than several ounces of pressure you’re bound to be wasting energy.
For example, if I shut off half my radiators and allow the pressure to rise to 3psi, the cycle length is almost as long as it is with all the radiators open but at much lower pressure. It’s not hard to see that one could spike fuel use tremendously if the pressure is too high for the task at hand. There is such a thing as a Vaporstat that is like your boiler’s pressuretrol but it’s calibrated in ounces. It may be worth investigating.

A steam heating system out of calibration can be an energy hog. One that’s dialed in should be very economical to run, all other things being equal. Obviously heat loss is the other half of the picture. But start with confirming optimum steam system operation since it’s on your mind already