ProLine is AO Smith's mid-tier plumber-channel residential line — 6-year standard warranty (9-year upgrade available), sold through licensed plumbers and HVAC contractors.
The ProLine lineup
- ProLine XE 50G Power Vent (GPV-50) — mid-tier 50G power vent gas
- ProLine XR Power Vent 50G (GPVH-50) — premium variant with higher recovery
- ProLine 30G Electric (PNS-30) — small-application electric
- ProLine Tankless 10 GPM (ATI-540H-N) — AO Smith's tankless flagship
- ProLine Tankless 6.5 GPM (ATI-110U) — smaller tankless variant
ProLine Tankless
The ProLine Tankless line is AO Smith's gas tankless flagship. ATI-540H-N at 10 GPM peak flow with 15-year heat exchanger warranty is the longest tankless warranty in the residential market. Competitive with Rinnai Sensei and Navien NPE-A2.
Bottom line
ProLine is the AO Smith mid-tier plumber channel. For premium tier step up to ProLine Master; for Lowe's retail equivalent see Signature Premier.