Lennox Heat Pump Water Heater 40-Gallon (WHHP050T45MD240S)
Lennox Heat Pump Water Heater 40-Gallon (WHHP050T45MD240S) is a heat pump (hybrid electric) water heater from Lennox with a 45 gallon rated tank and a 69 gallon first-hour rating at a 3.83 UEF.
| Uniform Energy Factor (UEF) | 3.83 |
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| Annual electricity use | 848 kWh/yr |
| Recovery efficiency | 437 % |
| Fuel | Electric |
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| First-hour rating | 69 gal |
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| Rated storage volume | 45 gal |
| Draw pattern | Medium |
| Heat pump type | 240 Volt Integrated HPWH |
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| Refrigerant (GWP) | R-513A (GWP:630) |
| Compressor low-temp cutoff | 35 °F |
| Input voltage | 240 |
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| Max current draw | 21 A |
| Smart / connected capable | Yes |
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| Height | 45.8 in |
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| Diameter | 18.2 in |
| ENERGY STAR certified | Yes |
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Who is the Lennox Heat Pump Water Heater 40-Gallon (WHHP050T45MD240S) for?
- Its 69 gallon first-hour rating suits a household of 3–4 people under DOE sizing guidance.
- Estimated running cost: about $144/year at the national average electricity rate (848 kWh/yr certified use).
- Needs a 240 V circuit; at 21 A max draw plan for a 30 A breaker (NEC 125% continuous-load rule).
- The heat pump compressor operates down to 35 °F ambient — below that, backup elements take over.
Similar water heaters
- 1HVAC Heat pump water heater 50-Gallon (UEF 3.75)
- ACIQ Heat pump water heater 50-Gallon (UEF 3.75)
- Alsetria heat pump water heater 50-Gallon (UEF 3.75)
- Ariston Heat Pump Water Heater 40-Gallon (ARIHPWH-50-T) (UEF 3.83)
- Bosch Water heater 50-Gallon (UEF 3.75)
- Custom Comfort heat pump water heater 50-Gallon (UEF 3.75)
Frequently asked questions
Is the Lennox Heat Pump Water Heater 40-Gallon (WHHP050T45MD240S) ENERGY STAR certified?
Yes, the Lennox Heat Pump Water Heater 40-Gallon (WHHP050T45MD240S) holds a current ENERGY STAR certification for water heating efficiency (UEF 3.83).
How much does the Lennox Heat Pump Water Heater 40-Gallon (WHHP050T45MD240S) cost to run per year?
About $144 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 Lennox Heat Pump Water Heater 40-Gallon (WHHP050T45MD240S) need?
The Lennox Heat Pump Water Heater 40-Gallon (WHHP050T45MD240S) runs on a 240 V circuit drawing up to 21 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 Lennox Heat Pump Water Heater 40-Gallon (WHHP050T45MD240S) a smart water heater?
Yes, the Lennox Heat Pump Water Heater 40-Gallon (WHHP050T45MD240S) is connected-capable, with app control and eligibility for most utility demand-response programs.
Sources
- data.energystar.gov (retrieved 2026-07-17)