When you need more hot water from a tank heater or want to improve on-demand performance, a dedicated water heater booster can be the right upgrade. These devices boost deliverable hot water by raising the effective output of your existing system. Ideal for small homes, bathrooms, or under-sink setups, boosters are best for buyers seeking a compact, install-friendly solution with clear temperature control. The following five products are strong choices for increasing hot water delivery, with notes on who they’re best for and where they shine.
Quick comparison at a glance:
| Product | Best For | Main Benefit | Limitations |
|---|---|---|---|
| Rheem RTEX-AB Water Heater Booster | Mid-sized homes; general use | Compact, reliable booster with simple install | Average output; check compatibility with your heater |
| Eemax TankBuddy Water Heater Booster Blue | Any tank size; high gain | Up to 45% more deliverable hot water | Requires appropriate wiring and breaker |
| EcoSmart ECOTB240 | Electric upgrades; budget-conscious | Up to 45% more hot water; adjustable temp | Requires 240V circuit; not for showers |
| Eemax HATB007240 Tank Booster | Compact spaces; precise control | High accuracy temp; external controls | Limited to 7.2 kW; depends on supply |
| Cash Acme 24644 Tank Booster | Tempered water safety; multiple heater types | Integrated mixing valve to prevent scalding | Requires PEX/CPVC copper piping work |
Rheem RTEX-AB Water Heater Booster
The Rheem RTEX-AB Booster is a compact addition designed to increase hot water delivery from existing storage or tankless systems. It weighs about 5.64 pounds and measures 8-1/4″ high by 12-5/8″ wide by 3-5/8″ deep, making it a feasible upgrade for installations with space constraints. Best for homeowners seeking a straightforward, space-saving booster that integrates with standard plumbing.
Best for: small to mid-sized homes needing a reliable, easy-to-install boost. Why selected: Rheem’s familiar control approach and compact form factor simplify integration with many water heaters.
Caution: Verify compatibility with your current heater’s electrical and water connection layout before purchase. Ensure wiring meets local codes and is sized for the booster’s requirements.
Eemax TankBuddy Water Heater Booster Blue
The Eemax TankBuddy Blue is designed to push more hot water from any tank, with claims of up to 45% more deliverable hot water. It can operate with existing 10 gauge wiring and a 30 AMP breaker, potentially avoiding additional feeds in some setups. This makes it a flexible option for owners seeking greater supply without major electrical upgrades.
Best for: homes needing a noticeable increase in hot water without a heavy electrical install. Why selected: Strong performance gain and wiring flexibility can suit retrofit projects.
Caution: Confirm your electrical panel and wiring configuration supports the booster and that the 30 AMP breaker matches local code requirements.
EcoSmart 7.2 kW Electric Water Heater Booster ECOTB240
The EcoSmart ECOTB240 booster adds 7.2 kW of electric resistance to increase deliverable hot water by up to 45%. It’s designed for scenarios where the existing circuit supports 240V operation and user-configurable activation temperature (80-130°F). It’s a practical choice for electric-only installations where space is at a premium.
Best for: households with 240V electrical capacity seeking a budget-friendly, adjustable-tuning booster. Why selected: Clear temperature control and a sizable gain in hot water output.
Caution: Not suitable for showers in some flow conditions; ensure the outlet temperature and flow rate meet your needs before installing.
Eemax HATB007240 Tank Water Heater Booster 7.2 kW
The Eemax HATB007240 booster offers a compact design with zero clearance requirements and a digital user interface. It increases deliverable hot water up to 45% and provides temperature precision within +/- 1 degree Fahrenheit, with external controls for adjusting settings. This makes it suitable for tight spaces and precise control needs.
Best for: space-constrained installations where precise temperature control matters. Why selected: Compact form with accurate temperature regulation and digital controls.
Caution: Its 7.2 kW rating means you must confirm compatible electrical supply and breaker sizing for your installation scenario.
Cash Acme 24644 Tank Booster With Mixing Valve
The Cash Acme 24644 combines a tank booster with a thermostatic mixing valve, temperature gauge, and compatible piping options (PEX, PE-RT, CPVC, copper). It subtly blends hot and cold water to deliver a tempered output at a safe, controlled temperature. This is ideal for preventing scalding in showers and other outlets.
Best for: households prioritizing safe, tempered water alongside boosted delivery. Why selected: Integrated mixing valve reduces scald risk and supports varied plumbing configurations.
Caution: Installation involves connections to PEX/CPVC or copper piping—plan for proper fittings and space for valve access.
Buying Guide
What to consider when choosing a tankless water heater booster:
- Electrical compatibility: Check voltage (120V vs 240V) and breaker requirements. Some boosters require dedicated circuits, especially higher-wattage models.
- Flow rate and temperature gain: Assess the expected GPM increase and the target temperature rise for your typical usage (shower, sinks, dishwasher).
- Space and installation: Measure available space and assess whether the booster needs to be mounted near the heater, under a sink, or in a utility closet.
- Safety features: Look for temperature limiting, anti-scald controls, leakage protection, and dry-run protection to prevent damage.
- Compatibility: Ensure the booster is compatible with your existing heater type (gas, electric, tankless) and piping materials (PEX, CPVC, copper).
- Control interface: Consider digital displays or external controls for easy adjustment and monitoring of output.
FAQ
- Do tank booster devices work with all water heaters?
Booster devices are designed to work with many standard water heaters, but compatibility depends on electrical supply, piping, and the heater type. Always verify with the manufacturer’s guidelines.
- Will a booster increase hot water for showers only?
Boosters generally increase overall hot water delivery, benefiting showers and other outlets. Specific gains depend on the unit’s output and system setup.
- Is an electric booster necessary if I already have a tankless system?
Not always. A booster can help if your existing system struggles to meet simultaneous hot water needs or if a tankless unit lacks sufficient capacity for peak demand.
- What maintenance does a booster require?
Maintenance is typically minimal but may include periodic inspection of connections, cleaning any mineral buildup on valves, and verifying electrical safety and insulation.
- How do I know which booster to pick?
Match the booster to your electrical capacity, space, and the level of hot water increase you need. For tight spaces, a compact model with precise temperature control may be best.