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Maximus Takes Performance and Efficiency to the Max
December 22, 2025
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LinkedIn Why Rheem’s Maximus Line Raises the Bar in High-Efficiency Gas Water Heating
Rheem’s Maximus family represents one of the most significant evolutions in residential gas water heating in recent years. Designed to deliver “super high efficiency,” the Rheem Maximus line is built for homeowners who want a powerful, reliable gas water heater that also reduces energy use, lowers utility bills, and simplifies installation and servicing. Instead of choosing between performance, efficiency, and smart technology, the Maximus provides all three, making it a standout solution for modern homes.
With tightening efficiency standards and increasing homeowner interest in energy savings, Rheem developed Maximus to exceed current expectations. Each model in the family—Maximus, Maximus with LeakSense™, Maximus Heavy Duty (HD), and Maximus Plus—uses a condensing design that captures more heat from exhaust gases. These models meet ENERGY STAR® 5.0 requirements, incorporates advanced combustion control, offer flexible venting, and meets regulatory requirements that reduce greenhouse gas emissions and environmental impacts.
Homeowners benefit from powerful performance, consistent hot water availability, and smart control features, while contractors gain front-side servicing, flexible venting options with one unit, and start-up verification to ensure customers are up and running at the initial install.
How Maximus Delivers Maximum Efficiency
At the heart of the Maximus story is efficiency. Thanks to their condensing vent design, Maximus units reach Uniform Energy Factor (UEF) ratings up to 0.90, significantly above traditional gas tanks in the 0.60–0.65 range.
The Maximus line is designed to support cleaner home operation and compliance with low-emission requirements. Maximus models reduce NOx emissions by up to 75% compared with a typical atmospheric gas water heater. Maximus models also deliver up to 2.5× the hot water of a standard 50-gallon tank, thanks to their rapid recovery rates and ability to maintain continuous flow better than non-condensing systems.
Because they meet ENERGY STAR® 5.0 guidelines and achieve the highest tiers within the Consortium for Energy Efficiency (CEE), Maximus units may qualify for local rebates and incentives, helping homeowners offset installation costs.
Explore tax credits and incentives.
Performance Features That Set Maximus Apart
While efficiency drives the engineering behind Maximus, performance defines the user experience. Rheem built the product line to ensure homeowners never feel limited by hot water capacity, even during peak use.
One standout feature is MaxMode™, a high-demand performance boost that delivers up to 15% more hot water for up to seven simultaneous showers for the 50-gallon model and nine simultaneous showers for the 75-gallon model.. Whether a household is hosting guests or running multiple appliances, MaxMode™ ensures the tank keeps up without compromising comfort.
Another homeowner-focused feature is the Hot Water Availability Indicator, which shows how much hot water remains inside the tank. This small addition makes everyday planning easier, especially for families with staggered shower routines.
On select models, LeakSense™ provides leak detection in under 15 seconds, alerting users immediately. When paired with the optional LeakGuard™ automatic shutoff accessory, the system can limit water release to just ounces instead of gallons.
Smart connectivity through EcoNet® brings temperature adjustment, energy consumption tracking, scheduling, and diagnostic alerts directly to a smartphone. This gives homeowners more transparency and control, which is increasingly expected from modern home systems.
These features make Maximus much more than a high-efficiency tank. It’s a smart, performance-driven water heating platform designed to meet real household demands.
Comparing the Maximus Models: Premium and Plus Models
The Rheem® Maximus Plus family gives homeowners a choice of capacity, features, and smart-technology level so you can select the right version for your home’s needs.
Maximus® (Plus Model)
This version provides the core Maximus benefits of high efficiency, strong performance, and installer-friendly design, without some of the premium smart features. It’s designed for homeowners who want efficiency and performance upgrades, but don’t need built-in leak detection or WiFi connectivity.
Maximus® with LeakSense™ (40 & 50G Premium Model)
This model adds smart monitoring and built-in leak detection. It carries a 12-year limited tank & parts warranty and features built-in leak detection (LeakSense™) and WiFi connectivity for remote monitoring.
Maximus® HD with LeakSense™ (75G Premium Model)
The HD model is built for larger homes and higher-demand usage. This model expands the Maximus lineup with a 75-gallon tank capacity while preserving the same efficiency and smart features found in the LeakSense™ models. Someone with multiple bathrooms or simultaneous uses may prefer the HD model rather than the smaller sizes.
Maximus® (40 & 50G Plus Model)
This variant is intended as a cost-efficient version of the Maximus platform. It retains high efficiency and many of the practical installation features, but with a somewhat streamlined feature set. Features include a first-hour rating up to 95 gallons (depending on model), recovery up to 64 GPH at a 90°F rise (depending on model) for this version. The warranty for the plus version is a 9-year limited tank & parts option.
Common Features Across All Maximus Models
- Use a condensing gas burner design to achieve high efficiency with UEF values up to around 0.90 per Rheem’s published materials.
- Provide up to 2× faster heating than a standard gas tank in some conditions.
- Installer-friendly design: zero side clearance in many installations, front service access, flexible venting (Power Vent or Power Direct Vent) in one SKU.
- Built-in condensate neutralizer (on those models that include condensing venting) plus long venting runs and side water connections (in select models) for integration with space-heating.
- Eligible for ENERGY STAR® listing and local incentives/rebates (depending on region) thanks to their high-efficiency operation.
Learn more about the Maximus lineup in our previous blog.
Installation, Service, and Maintenance Advantages
A major strength of the Maximus family is its installer-friendly design. Rheem built the line to reduce labor time and simplify both initial installation and future servicing.
All Maximus units offer zero side clearance, a major advantage for tight closets or basements. Every primary serviceable component is accessed from the front, which helps technicians diagnose and repair units without repositioning the tank.
Rheem also simplified venting by designing a single SKU to support both Power Vent (PV) and Power Direct Vent (PDV) applications. This reduces ordering complexity for distributors, contractors, and homeowners.
The units feature advanced digital diagnostics with full-text error codes, an LCD display, and (on smart models) diagnostic logs available through the EcoNet® app. Routine, annual water heater maintenance remains straightforward. Annual flushing, anode inspection (for models with anodes), venting checks, and condensate inspection help ensure optimal performance over the lifespan of the unit.
Whether you’re a homeowner or a plumber, the Maximus line is designed to reduce headaches, speed up installation, and ensure dependable servicing.
More questions? Contact a Rheem pro today.
Conclusion: Maximum Efficiency, Performance, and Confidence
Rheem’s Maximus line combines efficiency, performance, and intelligence into a single family of products that provides the modern solution many households are looking for. Homeowners get more hot water, lower energy bills, and features that improve day-to-day comfort. Installers enjoy easier venting, service access, and diagnostic clarity. With multiple models tailored to different needs and budgets, the Maximus family delivers a compelling, future-ready solution for high demand homes.
Explore the Maximus from Rheem
FAQ
Q: How much can I save with a Maximus compared to a standard gas tank?
Homeowners may save up to $1,100 over 12 years and reduce energy use by up to 36% when paired with a recirculation pump, based on Rheem’s internal testing. Actual savings vary by usage and fuel costs.
Q: Will Maximus qualify for tax credits or rebates?
Yes. Because Maximus meets ENERGY STAR® 5.0 and CEE Tier requirements, it generally qualifies for many local rebates and may qualify for certain federal incentives (subject to program changes). Always verify current eligibility.
Q: Can Maximus deliver continuous hot water like a tankless system?
While it is still a tank system, Maximus models heat water up to 2× faster than a standard gas tank and, in some cases, provide up to 2.5× the hot water of a typical 50-gallon unit. With MaxMode™, some households will experience performance approaching tankless-like availability.
Q: Do I need LeakGuard if the unit has LeakSense?
LeakSense™ detects leaks quickly and alerts you, while LeakGuard™ adds an automatic shut-off to limit water to around 20 ounces. LeakGuard™ is ideal for installations near finished floors, closets, or valuable belongings.
Q: What advantages do installers get?
Front-side servicing, simplified venting (PV/PDV in one SKU), integrated diagnostics, long vent runs, and zero-clearance installation all help streamline the installation process and support easier long-term maintenance, and with Start-up Verification you can ensure your customer is fully up and running at the initial install by confirming proper system operation and verifying all key performance settings before leaving the job site.
