Plumbing and drain companies in the 10-to-50-person range mostly run Housecall Pro, Jobber or ServiceTitan, with QuickBooks behind them. Two AI uses pay reliably. One is call coverage: water-heater and backup calls do not wait for voicemail, so after-hours and overflow answering earns its fee quickly if you actually miss calls. The other is plain automation, not AI: web and Google leads flowing straight into jobs, with a confirmation text, which removes 4 or 5 minutes of re-keying per lead. A third, smaller win is drafting membership renewals. Ignore chatbots on your website that cannot book into your real schedule.