Water Heater Boosters: An Efficient Solution for Increasing Hot Water Capacity

As household hot water demands continue to grow, many homeowners find that their existing water heater struggles to keep pace with daily usage. Multiple showers, laundry cycles, dishwashing, and other simultaneous hot water demands can quickly deplete available hot water, leading to inconvenience and homeowner frustration.

Traditionally, the solution has been to replace the existing water heater with a larger-capacity model. However, a water heater booster offers an alternative approach by increasing the usable hot water delivered from an existing storage tank. This cost-effective upgrade can improve performance, extend hot water availability, and help homeowners maximize the value of their current water heating system.

What Is a Water Heater Booster?

A water heater booster is an accessory installed on a water heater’s hot water outlet that increases the amount of usable hot water available from a storage tank. The booster activates when it senses the tank has run out of hot water and makes up the difference, which effectively increases the capacity of the existing water heater without requiring a larger tank.

This technology allows homeowners to meet higher hot water demands while maintaining their current water heater installation.

Key Benefits of a Water Heater Booster

Increased Hot Water Availability

One of the most significant advantages of a water heater booster is its ability to increase available hot water capacity. The Rheem Performance^® RETEX-AB7 Water Heater Booster can increase available hot water by up to 60%, helping households meet peak demand periods with greater confidence.1 It can also provide 15 minutes or more of additional shower time under typical operating conditions.2

This additional capacity can be particularly beneficial for households with:

• Large families
• Multiple bathrooms
• Back-to-back showers
• High morning hot water demand
• Frequent overnight guests

Cost-Effective Alternative to Tank Replacement

When homeowners begin to experience hot water shortages, many assume a larger water heater is required. In many cases, however, a water heater booster can provide the added performance needed without replacing the existing tank.

By leveraging the storage capacity already available, homeowners can often avoid the cost and disruption associated with complete water heater replacement.

Improved Comfort and Convenience

Running out of hot water can interrupt daily routines and diminish homeowner satisfaction. A water heater booster helps ensure hot water remains available longer, supporting activities such as showering, laundry, and dishwashing without compromising comfort.

High-Efficiency Operation

Modern water heater boosters utilize advanced self-modulating technology that adjusts power consumption based on actual demand. This means the unit only uses the energy necessary to maintain the desired outlet temperature, contributing to efficient operation while delivering enhanced performance. The booster only comes on when it detects a drop in the desired temperature. The Rheem RETEX-AB7 features a Uniform Energy Factor (UEF) of 0.96.

When Should a Water Heater Booster Be Considered?

Water heater boosters are an ideal solution in several common scenarios. Particularly, the booster is an ideal addition to electric tanks where an additional circuit is not required.

Growing Household Demand

As families grow and hot water usage patterns change, an existing water heater may no longer provide sufficient capacity. A booster can help address increased demand without requiring a larger tank.

Limited Installation Space

Many homes have physical space constraints that make upgrading to a larger water heater impractical. Because a booster is compact and can be mounted directly on the tank outlet or on a nearby wall, it provides additional hot water capacity without increasing the system footprint.

Existing Water Heater Still Has Service Life Remaining

If a water heater remains in good condition but no longer satisfies demand, a booster can be an economical way to improve performance and extend the usefulness of the existing equipment.

Remodeling and Home Improvements

Bathroom additions, kitchen renovations, and other home improvement projects often increase hot water demand. Installing a water heater booster can help accommodate these changes without requiring complete system replacement.

Benefits for Homeowners

For homeowners, a water heater booster offers several practical advantages:

• More available hot water during peak usage periods
• Extended shower duration
• Improved household comfort and convenience
• Lower investment compared to replacing a functioning water heater
• Better utilization of existing equipment
• Minimal space requirements

By increasing effective hot water capacity, a booster can help homeowners solve performance challenges while controlling upgrade costs.

Benefits for Plumbing Professionals

Water heater boosters also provide meaningful value to plumbers, contractors, and service professionals.

Expanded Solution Portfolio

Not every hot water complaint requires a new water heater. A booster provides a practical alternative that allows contractors to address capacity concerns without recommending a full replacement.

Flexible Installation Compatibility

The Rheem RTEX-AB7 Water Heater Booster is compatible with standard electric, gas, smart electric, and heat pump water heaters, making it a versatile solution for a wide range of residential applications.

Enhanced Customer Satisfaction

Customers benefit from increased hot water availability and improved system performance, while contractors gain the opportunity to deliver a cost-effective solution that addresses a common homeowner concern.

Features That Deliver Performance

Today’s water heater boosters include advanced features designed to simplify operation and enhance system performance. The Rheem RETEX-AB7 offers:

• Digital LED user interface
• Precise temperature adjustment in 1-degree increments
• Flow monitoring capabilities
• Load factor monitoring
• Vacation/Away mode (electric tank installations only)
• Durable ¾-inch metal water connections
• Flexible wall or tank-mounted installation options
• Side and bottom wire entry ports

These features provide greater visibility into system operation while helping maintain consistent hot water delivery.

Give Your Water Heater a Boost

Water heater boosters represent an innovative and practical solution for homeowners seeking additional hot water capacity without replacing their existing water heater. By increasing the amount of usable hot water available from a storage tank, these devices can enhance comfort, improve system performance, and provide a cost-effective alternative to tank replacement.

For plumbing professionals, water heater boosters offer a versatile upgrade option that can address homeowner concerns, improve customer satisfaction, and create additional business opportunities. As residential hot water demand continues to increase, booster technology provides an effective way to maximize performance while leveraging existing water heating infrastructure.

Rheem Performance Tank or Tankless Water Heater Booster 7kW (240V) RETEX-AB7 – The Home Depot

Spec Sheet

U&C Manual

¹Water Heater Booster can increase the hot water delivery capacity of electric water heater tanks to deliver water at 98°F or hotter by as much as 60% for a 2.5 GPM standard showerhead. Standard showerheads use 2.5 gallons of water per minute (GPM) www.epa.gov/watersense/ showerheads. ²Water Heater Booster can extend the duration of delivery of water from a 40-gallon or higher capacity electric standard water heater tank at 98°F or hotter to 1.5 and 2.5 GPM showerheads by 19.6 and 15.1 minutes, respectively. According to testing by an independent test agency