Is the REHP80 right for your home?
The Rinnai REHP80 is an 80-gallon nominal hybrid electric water heater with 74 gallons of rated storage and a 91-gallon first-hour rating. Its larger hot-water reserve is worth comparing when showers, laundry and bathing regularly overlap. Actual demand still determines sizing; an 80-gallon label is not a guarantee that every household schedule will be covered.
At this size, the route into the house or garage matters as much as the final location. WHE checks doorways, overhead obstructions, floor support and access for future maintenance before recommending the REHP80.
Verified Rinnai REHP80 specifications
| Nominal capacity / rated storage | 80 gallons / 74 gallons |
|---|---|
| Type / energy source | Hybrid heat pump with electric resistance elements / electric |
| Uniform Energy Factor | 4.00 UEF |
| First-hour rating | 91 gallons |
| Listed recovery at a 90°F rise | 27.5 gallons per hour |
| Power supply / breaker | 208–240V, 60Hz, single phase / 30 amps |
| Electrical ratings | 4,500W element rating; 500W compressor; 5,000W total input; 21.5A maximum current |
| Drawing A: height / B: diameter | 74.2 / 25.6 inches |
| Water connections | ¾-inch MNPT hot and cold side connections |
| Condensate connection | ¾-inch male barb / hose connection in the manual |
| Approximate unit weight in specification sheet | 290 lb |
| Limited warranty | 10 years tank and other parts; 1 year reasonable labor, subject to the applicable warranty terms |
First-hour rating measures delivery under standardized conditions; it is not the amount of water stored. UEF is an efficiency comparison, not a prediction of your bill. Room temperature, inlet water temperature, operating mode and usage affect performance. The listed recovery figure should not be treated as a heat-pump-only recovery rate.
Dimensions, service access and document differences
The REHP80 drawing lists A = 74.2 inches high and B = 25.6 inches in diameter. Those dimensions do not include the working room needed for side connections, a drain pan, service panels, filter removal or anode replacement. The specification sheet lists an approximate empty weight of 290 pounds; the floor must support the filled heater, not just its empty weight.
Rinnai’s product-page summary instead gives 74.5625 inches high × 25.69 inches wide and 270 pounds. This guide uses the labeled A and B dimensions and weight in specification sheet 800000224(03), December 2025, linked from that model page. Because those published figures differ, WHE confirms the exact supplied unit and drawing before a tight-space installation.
Airflow, electrical supply and condensate
This is an indoor electric heater. It draws heat from the air and releases cooler air, so WHE evaluates usable room volume, air movement and operating sound. A garage may work well; a small enclosed closet needs a suitable ventilation or ducting arrangement. Air ducts are not a combustion flue.
Rinnai’s manual shows an unducted arrangement with more than 700 cubic feet of free room volume and separate options for smaller spaces. Its clearance table lists 6 inches on the left and 2 inches on the right, while recommending 12 inches at the sides and 20 inches above for service and performance. These examples must be checked against the complete installation instructions and actual air path.
WHE verifies the 208–240V supply, 30A circuit and equipment nameplate. This is not a 120V plug-in model. The manual describes the heat-pump air-temperature operating range as 3–42°C, approximately 37–108°F; Rinnai’s sheet rounds it to 37–107°F. Avoid choosing a location on the assumption that heat-pump operation is unrestricted in very hot or cold air.
The manual specifies a ¾-inch barbed condensate connection, although the website’s summary labels it MNPT. We inspect the supplied fitting and arrange drainage or a suitable condensate pump. Condensate must not discharge into the water-heater drain pan. Water pressure, thermal expansion, relief-valve discharge and leak protection are also part of the installation review.
Operating modes and optional leak protection
The series offers Economy, Heat Pump, Hybrid, E-Heater and Vacation modes. Resistance heating can help meet demand, but greater element use changes energy consumption. The CTA-2045 port supports compatible demand-response equipment; it should not be mistaken for an included Wi-Fi controller.
Rinnai lists leak kit 103000119 and ducting kit 103000120 as optional accessories. Do not assume that a bare REHP80 includes a leak sensor or automatic water shutoff. WHE confirms the accessories included in the proposed installation.
Vacation Mode requires a mixing valve. Rinnai’s September 2026 Technical Bulletin 217 applies to this model. At the end of a vacation cycle, stored water can reach approximately 140–149°F for the tank-cleaning cycle. Rinnai says not to use Vacation Mode without a correctly installed and working ASSE 1017 thermostatic mixing valve. Have a qualified installer verify the valve and delivery temperature before using this feature.
Compare the REHP50 and REHP80
| Model | Nominal / rated capacity | UEF | First-hour rating | Drawing A × B |
|---|---|---|---|---|
| Rinnai REHP50 | 50 / 46 gal | 3.75 | 73 gal | 66.4 × 21.7 in. |
| Rinnai REHP80 | 80 / 74 gal | 4.00 | 91 gal | 74.2 × 25.6 in. |
Compared with the REHP50, the REHP80 provides 28 more gallons of rated storage and an 18-gallon increase in first-hour delivery. Its drawing height increases by 7.8 inches and diameter by 3.9 inches. Both models list the same 27.5 GPH recovery at a 90°F temperature rise. The larger model’s main advantage here is storage and first-hour delivery, not a higher published recovery rate.
For a large tub or closely spaced showers, WHE reviews the amount of hot water drawn and the time available between uses. Where a home has a recirculation system, we also review the return piping and controls because circulation losses add to the heating load.
Maintenance and limited warranty
Keep the air filter, condensate route and service panels accessible. Rinnai recommends cleaning the air filter every three months; sediment and anode maintenance also need attention according to water conditions and the manual.
The manufacturer’s limited warranty lists 10 years for the tank and other parts and one year of reasonable labor for covered defects. Qualified installation, proper maintenance, proof of purchase and other conditions apply. It is not blanket coverage for every removal, installation or service expense.
Manufacturer documents and local installation
Review the Documentation section of Rinnai’s official REHP80 product page for specification sheet 800000224(03) and the installation manual. At our October 17, 2026 review, the download labeled 100000867(04) delivered 100000867(05), July 2026. The September 2026 Vacation Mode bulletin above adds guidance that must be considered with the manual.
For Palm Beach Gardens, Jupiter and nearby Palm Beach County homes, WHE compares the existing installation, peak demand and available space before confirming equipment and installation scope. See our Rinnai installation page, hybrid water heater service and water heater model catalog. Share photos of the current heater and label when requesting an estimate.
Rinnai REHP80 FAQs
How much water does the REHP80 actually store?
It is sold in the 80-gallon class and lists 74 gallons of rated storage. Its 91-gallon first-hour rating measures delivery during the test’s first hour, rather than stored capacity.
Can the REHP80 replace my existing electric tank?
Possibly. WHE checks physical fit, the electrical circuit, airflow, drainage and service access before recommending a replacement. A matching gallon label alone does not establish compatibility.
Does this model include automatic leak shutoff?
The manufacturer lists leak kit 103000119 separately. Confirm the accessories included in the actual equipment and installation proposal.
Can I use Vacation Mode when I travel?
Only after a qualified installer verifies a properly installed, functioning ASSE 1017 thermostatic mixing valve. Rinnai’s TB-217 explains that the end-of-cycle cleaning function can raise tank water to approximately 140–149°F.
What warranty does Rinnai list?
The limited warranty provides 10 years for the tank and other parts and one year of reasonable labor for covered defects, subject to its installation, maintenance and eligibility requirements. Review the certificate for the supplied unit.