A. O. Smith Heat Pump 50-Gallon (FPTU-50 1) is a heat pump (hybrid electric) water heater from A. O. Smith with a 46 gallon rated tank and a 66 gallon first-hour rating at a 3.35 UEF — 970 kWh/yr certified use, 63 in tall.
Our take
The value-line entry on A. O. Smith's slim 63-inch chassis: 3.35 UEF, bottom third of the 50-gallon class, at about $165 a year — exactly the cohort median cost and still roughly $450 under a standard electric tank. First-hour delivery is 66 gallons for 3–4 people. Its compressor cuts off at 45 °F, the highest threshold on this platform, so in a cool basement it leans on resistance elements sooner than the 37 °F versions. No connectivity. Five brand names, including U.S. Craftmaster, certify the identical unit.
Best for: Budget heat-pump entry in a warm mechanical room.
Trade-off: The 45 °F cutoff erodes savings in any space that gets cool.
Efficiency
Uniform Energy Factor (UEF)
3.35
Annual electricity use
970 kWh/yr
Recovery efficiency
407 %
General
Fuel
Electric
Capacity
First-hour rating
66 gal
Rated storage volume
46 gal
Draw pattern
Medium
Heat pump
Heat pump type
240 Volt Integrated HPWH
Refrigerant (GWP)
R-134a (GWP:1430)
Compressor low-temp cutoff
45 °F
Installation
Input voltage
240
Max current draw
22 A
Smart features
Smart / connected capable
No
Dimensions
Height
63 in
Diameter
15 in
Certification
ENERGY STAR certified
Yes
Who is the A. O. Smith Heat Pump 50-Gallon (FPTU-50 1) for?
Its 66 gallon first-hour rating suits a
household of 3–4 people under DOE sizing guidance.
Estimated running cost: about $165/year at the national
average electricity rate (970 kWh/yr certified use).
Needs a 240 V circuit; at 22 A max draw plan for a 30 A breaker (NEC 125% continuous-load rule).
The heat pump compressor operates down to 45 °F ambient — below that, backup
elements take over.
Also sold as
The A. O. Smith Heat Pump 50-Gallon (FPTU-50 1) is certified hardware that A. O. Smith and its partner brands
publish under 5 names. The same specifications apply to every
variant:
Is the A. O. Smith Heat Pump 50-Gallon (FPTU-50 1) ENERGY STAR certified?
Yes, the A. O. Smith Heat Pump 50-Gallon (FPTU-50 1) holds a current ENERGY STAR certification for water heating efficiency (UEF 3.35).
How much does the A. O. Smith Heat Pump 50-Gallon (FPTU-50 1) cost to run per year?
About $165 per year at national average energy rates, based on its certified annual energy use under the DOE test draw pattern. Your rate and usage change this figure.
What electrical circuit does the A. O. Smith Heat Pump 50-Gallon (FPTU-50 1) need?
The A. O. Smith Heat Pump 50-Gallon (FPTU-50 1) runs on a 240 V circuit drawing up to 22 A; per the NEC 125% continuous-load rule plan for at least a 30 A breaker (check the installation manual for the required circuit).
Is the A. O. Smith Heat Pump 50-Gallon (FPTU-50 1) a smart water heater?
No, the A. O. Smith Heat Pump 50-Gallon (FPTU-50 1) is not connected-capable — it has no app connectivity or demand-response support.
