Appliances / Heat pump water heaters / Giant
Giant GTHPCO-45 1**+GTXST-80 1** family
73 gal · split-system heat pump water heater
Check the price at the store, then add $3,088 of electricity to get the true cost. We may earn a commission if you buy through these links; as an Amazon Associate we earn from qualifying purchases.
- Price. Check what it costs at the store.
- Plus running cost. Add $3,088 of electricity over 13 years. That is the part the price tag hides.
- Compare. Pick your state below, then check the cheaper-to-run models of the same size.
About the Giant GTHPCO-45 1**+GTXST-80 1** family
The Giant GTHPCO-45 1**+GTXST-80 1** family is a 73 gal split-system heat pump water heater certified by ENERGY STAR. Its official test figure is 1,306 kWh of electricity a year, which at the U.S. average price of 18.19¢ per kWh comes to $238 a year, or $3,088 over a typical 13-year life.
For the same hot water, a standard electric tank water heater would use about 5,394 kWh a year, so this model uses 76% less electricity and saves about $744 a year.
Among 100 split-system models it ranks #66 for running cost. The cheapest model of this type would save $1,478 in electricity over 13 years, though it may differ in size and features.
If you want the same type and a similar size for less to run, the Smart Solar SSG2-ES 65 uses 893 kWh a year and would save about $977 over 13 years.
Listed features: smart / app control.
Cost to run where you live
1,306 kWh a year (ENERGY STAR test figure) × 18.19¢ per kWh, the average residential price in the U.S. for Jan–Aug 2026 (EIA). Your bill depends on your utility and how you use it.
Cheaper to run, same type and size
Or see every 66 gallons and up model ranked.
| Smart Solar SSG2-ES 65 | 65 gal | $162/yr | saves $977 |
| Smart Solar SSG2-ES 80 | 80 gal | $217/yr | saves $270 |
| Eco-Logical OMNI-80HP2-1A | 74 gal | $219/yr | saves $236 |
| Reclaim Energy MP80F-RC | 80 gal | $232/yr | saves $78 |
Specs
| Brand | Giant |
| Model | GTHPCO-45 1**+GTXST-80 1** |
| Type | split-system |
| Energy use | 1306 kWh / year |
| Federal maximum for this type | 5394 kWh / year |
| Size | 73 gal |
| Width | 20 in |
| Features | Smart / app control |
| Tank size | 73 gal |
| First-hour rating | 95 gal |
| Efficiency (UEF) | 3.80 |
| Usage pattern | High-Usage |
| Voltage | 240 |
| Tank height | 58 in |
| Tank diameter | 20 in |
Specs and energy use from the ENERGY STAR certified products list (U.S. EPA). An asterisk in a model number stands for colour or finish codes. HouseholdLeak is not affiliated with ENERGY STAR or the EPA.
Questions people ask
How much does the Giant GTHPCO-45 1**+GTXST-80 1** family cost to run?
About $238 a year at the U.S. average electricity price (18.19¢/kWh), based on its ENERGY STAR rating of 1,306 kWh a year. In a state with expensive power it can be much more; pick your state on this page to see your number.
How much will the Giant GTHPCO-45 1**+GTXST-80 1** family cost in electricity over its life?
About $3,088 over 13 years, a typical life for a heat pump water heater. Add that to the price you pay to get the true cost to own.
Is the Giant GTHPCO-45 1**+GTXST-80 1** family energy efficient?
Yes. It is ENERGY STAR certified and uses 76% less electricity than a standard electric tank water heater.
Is there a cheaper water heater to run of the same type and size?
Yes. The Smart Solar SSG2-ES 65 uses 893 kWh a year, about $977 less in electricity over 13 years.
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