AO Smith Signature Premier 40-Gallon Gas Water Heater

The AO Smith Signature Premier 40-Gallon Gas Water Heater (GCV-40-300) is AO Smith's volume mid-tier 40-gallon residential gas tank. Same 9-year warranty as the 50-gallon Signature Premier, same atmospheric burner, same Coregard anode and brass drain valve — just sized for 2–3 person households at a ~$100 lower price point.

Headline specifications

• Capacity: 40 gallons
• Fuel: Natural gas, atmospheric vent
• BTU input: 40,000 BTU/h
• First Hour Delivery: 75 GPH
• Recovery: 40 GPH at 90°F rise
• UEF: 0.67
• Warranty: 9-year tank and parts
• Anode: Coregard (aluminum-zinc, depletes slower than magnesium)
• Drain valve: Brass
• Dimensions: 50" H × 20" diameter

Who this model is for

The Signature Premier 40G is the volume-correct 40-gallon gas pick for 2–3 person households with existing natural gas service and atmospheric venting. Shorter form factor (50" vs 60"+ for some competing models) accommodates closets and tight basement installs that won't fit taller tanks.

Right buyer profile: homeowner doing a like-for-like atmospheric 40G replacement, shopping at Lowe's or via an AO Smith distributor, valuing the 9-year warranty without the WiFi feature of the Rheem Platinum equivalent.

Where it beats the alternatives

Vs Rheem Performance Platinum 40G ($949): AO Smith $100 less. Rheem ships 12-year warranty + EcoNet WiFi. AO Smith ships 9-year + no WiFi but with Coregard anode and brass drain valve. For non-WiFi buyers, the AO Smith is the value-equivalent pick.

Vs Rheem Performance Plus 40G ($749): nearly identical pricing and warranty. Choose AO Smith if your retailer is Lowe's; choose Rheem if Home Depot.

Vs State Select 40G Gas ($649): State is AO Smith's plumber-channel value brand — same manufacturing, 6-year warranty vs 9-year. Pay $150–$200 for the warranty extension if you'll keep the unit long enough.

Vs Whirlpool 40G Gas ($599): Whirlpool is AO Smith manufacturing at Lowe's value tier. Same hardware, 6-year warranty, no Coregard anode. Step up to Signature Premier for the warranty and durability features.

Where it falls short

0.67 UEF is class-typical for atmospheric gas — annual operating cost $200–$280 for typical 2–3 person demand.

Atmospheric venting limits closet and manufactured-home installs without power-vent variant.

No smart-home or WiFi integration. For buyers who want the Rheem Platinum's leak detection and remote temperature control, AO Smith's lineup doesn't have an equivalent at this tier.

Install considerations

50" height fits low-clearance closet installs that won't accommodate taller 40G tanks. 20" diameter standard. Existing atmospheric flue must be inspected and replaced if compromised.

1/2" gas line sufficient at typical runs. Install cost: $350–$700 like-for-like.

Maintenance

• Annual flush
• Coregard anode check year 4, replace year 6 (slower depletion than magnesium)
• T&P valve test annually

Bottom line

The AO Smith Signature Premier 40-Gallon Gas is the Lowe's-channel volume pick for 2–3 person households on natural gas atmospheric venting. 9-year warranty + Coregard anode + brass drain valve at a ~$100 discount vs Rheem Platinum equivalent (minus the WiFi feature). Shorter 50" form factor fits tighter installs. Click through to Amazon or visit Lowe's for live pricing.