State install requirements follow standard tank water heater rules with line-specific additions for Power Vent, Direct Vent, and Premier Hybrid heat pump.
All gas atmospheric units (ProLine, ProLine XE atmospheric, Sandblaster)
- Existing B-vent chimney with proper draft
- Gas line: ½" up to 40k BTU / ¾" for 50k+ BTU
- Combustion air: 50 cubic feet per 1,000 BTU/hr for confined spaces
- T&P discharge to floor drain or visible discharge location
- Drain pan with overflow (required when above living space)
Power Vent ProLine
- 120V dedicated outlet within 6 ft of unit
- PVC sidewall venting (2" or 3" depending on model)
- Vent length per installation manual (typically 65-100 ft equivalent)
- Termination clearances from windows, doors, grade per code
ProLine XE Direct Vent (GS6-50-XPDV)
- Two-pipe sealed combustion venting
- 120V outlet for inducer fan
- Vent up to 60 ft equivalent length
- Termination per code clearances
Electric ProLine
- 240V dedicated circuit, 30A breaker
- 10-gauge copper wire (most installs)
- T&P discharge
- Drain pan with overflow when above living space
Premier Hybrid heat pump
- 240V dedicated 30A circuit (same as standard electric)
- 700+ cubic feet of unconditioned air space around the unit (heat pump needs ambient air to operate)
- Ambient temperature 40°F+ for heat pump mode (below 40°F, unit defaults to resistance mode)
- Condensate drain — 4-8 gallons/day. Floor drain, sink trap, or condensate pump
- Clearances: 7" front (filter access), 4" sides, 7" top
- Headroom 80"+ recommended
- Noise: ~50-55 dB compressor noise — not appropriate for finished living spaces adjacent to bedrooms
Sandblaster commercial
- Same atmospheric gas requirements as residential ProLine
- Commercial code application — verify capacity meets occupancy demand
- 3-year commercial warranty applies (residential units installed commercially default to 3-year warranty)
Permits
Required in most US jurisdictions. Same permit requirements as AO Smith Signature installs.
Bottom line
Standard tank installs are within range of competent plumbers. Premier Hybrid heat pump install requires verifying the 700+ cubic feet of air space — most install failures stem from inadequate space leading to repeated lockouts and resistance-mode fallback.