For the furnace owner

One furnace on the board. Filter change on the Carrier Comfort 95 every 90 days, on a calendar line. Annual heat-exchanger / burner tune-up every 12 months, on its own calendar line. That is the whole list, and it lives on one due board.

You know the last filter. The filter was changed at Valley Comfort on August 12, 2026, and the invoice said $38. Say that date to Muse once and the row is written. Ninety days from August 12 is November 10, 2026, and the Worker counts the leftover days on the calendar: 37 left as of October 4. Book Valley Comfort for that week and the blower keeps moving clean air all heating season.

You know the tune-up too. The heat exchanger and burners were serviced at Valley Comfort on October 18, 2025, and the invoice said $189. Say that date once and the annual row is written, next due October 18, 2026. Book it before heating season and the first cold nights run on a furnace that has been brushed, scoped, and checked.

Before the first cold night, ask Muse what's due on the Comfort 95. The filter change comes back with November 10, 2026 and the 37 days left. The tune-up comes back with October 18, 2026. The Worker subtracts on the calendar and names what is left, and no model sits in the due path.

The calendar lines keep their dates. The filter change is every 90 days: old filter out, new filter in, airflow arrow toward the blower. The warm week that makes the filter easy to forget does not slide November 10's date. The heat-exchanger / burner tune-up is every 12 months: burners brushed and vacuumed, heat exchanger scoped for cracks, flame sensor cleaned, flue checked. The mild winter that lets heating season start late does not push October 18. A late tick is logged when it happened; the cadence does not move. These are the cadences you told Muse, not spec-sheet promises.

Your shop preference is one ask too. Say it once: Always Valley Comfort on the furnace. Muse writes it, and the next filter or tune-up booking starts at Valley Comfort without you naming the shop again.

The board can call ChatGPT too. Subscribe once and ChatGPT hears when a logged tick puts the filter or the tune-up on the board, in a signed webhook naming the job and how late. You did not have to ask first.

The day the house sells or you move out, say it once: sold. Muse archives the furnace and the due board drops it that day. Every filter row and tune-up row you logged stays in the history. If the deal falls through, one ask puts it back on the board.

The house log on /home-maintenance-checklist shows how calendar rows look. Copy the prompt on /for-your-agent and paste it into Muse. Free on Cloudflare Workers and D1.