Preventive maintenance
Also known as: PM, scheduled maintenance
Scheduled service visits performed before equipment fails, designed to extend equipment life and prevent costly emergency repairs.
Preventive maintenance (PM) is the discipline of servicing equipment on a regular cadence regardless of whether it's currently broken. The premise: a $150 spring tune-up that catches a degrading capacitor is dramatically cheaper than the $400 emergency call when that capacitor fails on a 95°F July afternoon.
Preventive maintenance is the operational engine behind maintenance plans (see related entry). The cadence varies by equipment: HVAC residential — twice yearly; commercial HVAC — quarterly; backflow devices — annually; chimneys — annually; pool equipment — monthly. Manufacturer warranties typically require documented annual maintenance to remain valid; skipped PM years can void coverage on expensive component failures. PM also serves as a cross-sell opportunity — the tech onsite for a tune-up can identify pending problems and propose work the customer wouldn't otherwise have called about.
Related terms
Maintenance plan
A recurring service contract bundling preventive visits at a flat monthly or annual price, typically with priority scheduling and a discount versus per-visit pricing.
Recurring service
Work that repeats on a schedule — weekly, monthly, quarterly — for the same customer at the same site.
First-time fix rate
The percentage of jobs resolved on the initial visit — without a callback, second trip, or escalation.