Furnace service timing depends on documented age and cost-ratio thresholds for repair viability

https://precisionhvacmultipoint.raidersfanteamshop.com/a-staged-assessment-determines-whether-your-system-needs-repair-or-full-replacement

Furnaces typically need annual professional tune-ups before the heating season, but the real question is when to service versus when that service investment no longer makes financial sense