HousemonthHousemonth / Guides
How often to change a furnace filter
Every three months: in January, April, July and October. The schedule is the same in every climate, so it is easy to remember as the first month of each season.
8 jobs a year, timed for mild winters. Tick them off as you go.
January
April
July
October
"Add these to my calendar" opens the free planner with this already ticked. Tick the rest of your house there, and it saves one calendar file that repeats every year.
The numbers, worked
One furnace filter changed every three months is 4 filters a year. A house with a furnace and a separate heat pump air handler has two filters to change, so 8 a year, in the same four months.
If you changed it in late November, the next change on this schedule is January, not February. Moving every change onto the same four months keeps one reminder doing the work.
Questions
Does my climate change how often I change the filter?
Not on this schedule: all four climate bands change it in January, April, July and October. What climate moves is the rest of the heating and cooling work, such as the tune-up before the cold.
What if the filter box gives a different interval?
Follow the box. Filters are sold with their own rated life, and the dates here are easy to move: change the reminder in your calendar to match.
Is a heat pump filter on the same schedule?
Yes. The heat pump filter is replaced or washed in the same four months. The planner adds it when you tick Heat pump.
Can I get a reminder?
Yes. "Add these to my calendar" opens the free planner with Furnace ticked. It saves a calendar file for Google Calendar, Apple Calendar or Outlook, and each change comes back on the first of its month, every year.