RELIANCE WATER HEATERS HPACO-45 1**+AXST-50S 1**
3.52 UEF DOE CCD · 2026-09-19Grade B: where this UEF sits among the 426 models in its class, lowest (G) to highest (A). A position, not an official label. How the grade is set
An electric tank, medium draw pattern (a typical three- or four-person household, about 55 gallons on a busy morning).
If you are checking the RELIANCE WATER HEATERS HPACO-45 1**+AXST-50S 1**, this electric tank uses 923 kWh of electricity a year at the medium draw pattern, the standard daily hot-water usage DOE tests against. That is 2,608 kWh below the 3,531 kWh median of the 426 electric tank models registered at the same draw pattern.
Energy use per year
923 kWh a year
Computed by this site from the registry's UEF and the federal test's daily hot-water draw for this draw pattern. What it costs depends on the electricity rate where you live.
That is below the median of 3,531 kWh for the 426 models registered in the same heater type and draw pattern; it ranks 70 of 426, lowest energy first.
Solid line: this model (923 kWh). Dashed line: the class median.
Min 773 kWh Median 3,531 kWh Max 3,569 kWh
What it costs to run where you live
What the registry files
- UEF (Uniform Energy Factor) how much hot water you get for each unit of energy the heater uses
- 3.52 DOE CCD · 2026-09-19 Compared only with other models registered as an electric tank at the medium draw pattern.
- Draw Pattern the standard daily usage profile DOE tests the unit against
- Medium DOE CCD · 2026-09-19
- First Hour Rating how many gallons of hot water the unit can deliver in one hour, starting from a full tank
- 70 gal DOE CCD · 2026-09-19
- Rated Storage Volume the tank size in gallons
- 46 gal DOE CCD · 2026-09-19
- On the market since (ENERGY STAR) the date the manufacturer told ENERGY STAR the model went on sale
- 2026-02-13 ENERGY STAR · 2026-09-19
- Connected / demand response (ENERGY STAR) whether the unit can take signals from your utility to shift when it heats, and by which standard (such as CTA-2045)
- Yes (CTA-2045-A,CTA-2045-B) ENERGY STAR · 2026-09-19
- Refrigerant and GWP (ENERGY STAR) the refrigerant a heat pump unit uses and its global warming potential, a leak's climate effect relative to carbon dioxide (CO2 = 1)
- R-744 (CO2), GWP 1 ENERGY STAR · 2026-09-19
What it costs to install
$3,030–$4,180 installed
Not a quote — a modeled range of what installers have charged for this class of unit; your price will vary with labor rates, access, and local code requirements.
Escalation indexes: equipment (BLS PPI) latest available: August 2026; labor (BLS ECI) latest available: April 2026 to June 2026.
NLR REMDB (BLS PPI/ECI escalated) · 2026-04-01Safety record
No CPSC recall names this model.
Checked against the CPSC recall database. CPSC does not publish a model-level match for this product category, so this list is curated by hand from the manufacturer's recall filings.
CPSC · 2026-09-24Does it fit your space?
Enter your own numbers below — this compares them to what ENERGY STAR publishes for this model, it does not tell you what to buy.
- Compressor operating range (ENERGY STAR)
- the air temperatures around the unit in which its heat pump runs; outside this range the heat pump stops
- Dimensions (ENERGY STAR)
- the unit's filed height, width, depth or tank diameter, in inches
- Input voltage and maximum current (ENERGY STAR)
- the circuit voltage the unit is certified on and the most current it draws
What these figures mean
How this compares
The closest models in the same class — same fuel, type and draw pattern.
Keep going
How every figure on this page is calculated
-
Find what replaces your water heater
Enter the model number off your old unit and see what is on file today, with the yearly cost difference.
-
Find a water heater that fits
Three questions — fuel, hot water need, install space — narrow every model on file to the ones that fit.
-
What a water heater costs to run
Prices a unit's efficiency against your own utility's filed tariff for your ZIP code.
-
What size heat pump water heater do I need?
Answered from what models in this size actually file.
-
Water heaters
Every model on file with the Department of Energy, by heater type.
-
All heat pump water heaters
Electric tanks that file a UEF of 2.0 or more — the registry has no separate heat pump type, so this site draws the line there.
-
All CO₂ (R-744) heat pump water heaters
Heat pump models whose ENERGY STAR filing names R-744 (carbon dioxide) as the refrigerant, a global warming potential of 1.
-
Every RELIANCE WATER HEATERS model on file
What this brand files, by heater type.
UEF 3.52 · Grade B Price it on your ZIP
The registry does not list the 923 kWh figure. This site computed it from the registry's UEF, the ratio of hot water delivered to energy used, and the DOE test's daily hot-water draw for the medium draw pattern. The DOE Compliance Certification Database lists a UEF of 3.52 for the HPACO-45 1**+AXST-50S 1**, retrieved 2026-09-19. So the figure holds only at the federal test's daily draw. It does not describe a household whose daily hot-water use differs from the test's. The registry gives no energy value for other levels of use, so that figure is not available here. The steps from UEF to annual energy are set out in how the annual cost is calculated.
The median comparison above covers the 426 models registered as an electric tank at the medium draw pattern. Within that group, the HPACO-45 1**+AXST-50S 1** ranks 70th lowest in energy use. The comparison does not extend to other fuels or other draw patterns. The registry gives a rated volume of 46 gallons. It also lists a first hour rating, the gallons of hot water available in the first hour from a full tank, of 70 gallons. The medium draw pattern represents typical household use, including a busy morning peak. A home whose morning peak exceeds 70 gallons falls outside what this rating covers. To check it against units in the same class, use find a same-class replacement by model number.
This text states no running cost, because the cost depends on your own utility's electricity tariff. The page calculates it from your ZIP, based on the 923 kWh figure at the medium draw pattern. Enter your ZIP in the cost calculator on your own ZIP to see that result. The 2,608 kWh gap below the class median is a difference in energy use. What that gap is worth depends on your rate. If you are checking a quote or a listing, first confirm that any energy figure it gives refers to the medium draw pattern. Only then compare it. The installed price range appears in its own block, with its source and date, as a modeled range rather than a quote. To look at other fuels or sizes, use the selector by fuel, space and size.
DOE CCD · 2026-09-19