Boiler unit on a 4-plex

[Jim Bice]

Hi all, my wife and I, after many years of analyzing, finally purchased an 4 unit apartment in western NY. Now that we are deep into the winter months we have noticed our heating bill (gas) continue to go up, our latest bill is over $400. We have a single boiler system with four zones and looking for advise or suggestions to lower the gas usage.  One thought was to move the thermostats from the apartments to a single conditioned space and place temperature monitors in each unit to make sure the apartments are at a comfortable level. We are not sure if one apartment or some are leaving windows open of if something else is happening. We have sent letters to each tenant asking them to be mindful and, if needed, to let us know if they have a maintenance issues with a window or door. Has anyone done this? Is there any other suggestions you may have?

Thank you

Jim