Check the simple items named in your manual
Confirm which filter fits the system and check it the way the manufacturer recommends. A clean filter is useful, but the correct size and replacement interval depend on the equipment and the filter selected.
Make a note of any register that has noticeably weaker airflow than the others and whether the same rooms were affected last season. Keep supply and return openings accessible rather than blocking them with furniture or storage.
Arrange service on the manufacturer’s schedule
The Maine Department of Energy Resources recommends yearly heating-system service for safe and efficient operation and describes routine cleaning for boilers and furnaces. A service visit can also identify wear and record findings before a no-heat call.
Keep fuel-burning equipment and alarms in view
Do not open the furnace cabinet, change wiring, or adjust fuel and combustion parts yourself. Report unusual odors, repeated shutdowns, smoke, and new sounds rather than repeatedly resetting the system.
The U.S. Fire Administration advises installing and maintaining carbon-monoxide alarms, including outside separate sleeping areas and on each level of a home. Follow its current safety guidance and the alarm manufacturer’s instructions.
Save the details that help with a service request
Keep the furnace model, fuel type, last service record, control messages, and the rooms affected in one place. If the system changes behavior during a cold period, those notes help explain what happened without opening the equipment.
Public guidance
These government publications are the sources cited in this guide. Equipment-specific instructions may differ.