American Standard's Standard Gas residential tank water heaters are atmospheric-vent and power-vent gas units manufactured by Reliance under the American Standard license. The Standard Gas line targets budget-conscious gas replacements in homes with existing gas service.
Atmospheric vent vs power vent
- Atmospheric vent: uses a natural draft chimney/vent (Type B). Simpler design, lower cost, no electrical required for venting. Vulnerable to backdrafting in tight modern homes.
- Power vent: uses a fan to actively push combustion exhaust through PVC venting. Allows horizontal venting through wall (no chimney needed). Higher upfront cost, requires 120V electrical for fan.
American Standard offers both — the appropriate choice depends on your existing vent infrastructure.
Standard Gas capacities
The line includes 40-gallon and 50-gallon configurations, typical 36,000–40,000 BTU/hr input. Recovery at 90°F rise: ~40 gallons per hour for 40-gallon, ~45 gph for 50-gallon. Higher recovery than electric tanks at the same capacity — gas heating typically delivers 2x the recovery of electric.
What "Standard Gas" includes
- Glass-lined steel tank
- Atmospheric-vent burner (or power-vent variant) with electronic intermittent or standing pilot ignition
- Magnesium anode rod (3/4" NPT)
- Standard T&P relief valve
- Brass or plastic drain valve depending on model
- Polyurethane foam insulation
Gas line sizing considerations
40,000 BTU/hr at 0.5 psi natural gas pressure demand approximately a 1/2" gas line for short runs (under 25 feet from meter). Longer runs or LP gas require 3/4". Verify your existing gas line is properly sized — undersized gas lines cause flame issues, soot, and (in severe cases) carbon monoxide problems.
Venting requirements
Atmospheric vent: 3" or 4" Type B vent pipe, rising at minimum 3/4" per foot of horizontal run, terminating per code (above roof line, away from windows and AC intakes). Power vent: 2" or 3" PVC, horizontal venting permitted through wall with proper termination, condensate considerations in cold climates.
Standard Gas vs alternatives
- vs Rheem Performance Gas: Rheem has cleaner warranty path and stronger US dealer network
- vs A.O. Smith Signature Gas: functionally similar (same OEM), A.O. Smith has slightly cleaner branding
- vs Bradford White Defender Gas: Bradford White carries longer warranty and plumber-only sales channel (which actually helps with install quality)
Where Standard Gas pencils out
Standard Gas is the budget-conscious gas replacement choice:
- Existing gas line and venting compatible with the unit
- Replacement scenario where the previous unit was a similar entry-tier gas tank
- Short to medium-term ownership where premium warranty isn't justified
- Familiar plumbing brand for whole-bathroom suite consistency
Common Standard Gas service issues
- Thermocouple/thermopile: pilot won't stay lit, $20–40 part replacement
- Anode rod: inspection at year 3, replacement at year 5
- Gas valve: typical replacement at year 7–10, $180–280 OEM
- Pilot orifice cleaning: as needed (spider webs in stored units)
- Vent inspection: annual, especially for atmospheric vent
Combustion air requirements
Atmospheric vent units require adequate combustion air — typically 1 square inch of vent per 1,000 BTU/hr. A 40,000 BTU unit needs 40 square inches of net free area in the install closet. Modern tight homes may starve atmospheric vent units, causing backdrafting and CO concerns. If your install closet doesn't meet combustion air requirements, the power vent variant or a sealed combustion direct-vent unit is the safer choice.