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Tank Max Hot Water Extender System

  • Double your water heater output
  • Easy to install
  • Prevents scalding by distributing water at safe temperatures
  • See More Details

Frequently Bought Together


Product Overview

More hot water. That's what TankMax by Apollo gives you. Innovative and easy to install, TankMax by Apollo is a thermostatic mixing valve engineered for installation on water heaters that uses a blend of hot and cold water to extend the amount of usable hot water to each point of use. Once the installation is complete, adjust the water heater output temperature to 140°F. By design, TankMax by Apollo will blend cold water with the 140°F to a comfortable 120°F. Through this process of storing hotter water and blending it with cold water, TankMax by Apollo virtually doubles the amount of usable hot water available for use without the need for replacing your hot water heater or adding an additional water heater. Storing water above 140°F has also been proven to eliminate the potential for Legionella bacteria growth. In the average installation situation, TankMax by Apollo can be installed by the do-it-yourselfer in less than half hour. Half an hour of work to double hot water output is an advantage only TankMax by Apollo can provide.
  • Lead-free dezincification resistant brass guarantees durability
  • Suitable for residential and commercial applications
  • Protects from scalding by distributing water at safe temperatures with a thermostatic mixing valve
  • Adjust desired water output temperature with the turn of a dial--factory-set to 120°F
  • Compatible with electric, gas and tankless water heaters
  • Inlets feature check valves and strainers to guarantee proper operation
  • Listed by IAMPO and certified to ASSE 1017 and NSF 61 and 372
  • CSA B125.3
  • Simple installation does not require glue or solder
  • Wrench and plumber's tape are the only tools required
  • Maximum supply pressure of 150 psi and temperature of 195°F
  • California residents

Info & Guides

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Product Depth (in.)
2.5 in
Product Height (in.)
16.5 in
Product Width (in.)
9.5 in


Potable Water
Compatible Brand/Model
Finish Family
Bronze/Copper Metallic
For Use With
Electric Tank,Electric Tankless,Gas Tank,Gas Tankless
Pack Size
Product Type
Product Weight (lb.)
2.90 lb

Warranty / Certifications

Manufacturer Warranty
2 Years: Must be installed per published installation instructions.

Questions & Answers

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Customer Reviews

  • 4
    out of 3 reviews
  • 50% recommend this product
Filter by:
Showing 1-3 of 3 reviews
Works as advertised
This product is a less expensive version of like products. It works as advertised and is adjustable if you’re not getting the temperature output you need. For ~$50 less than the next priced competitor its a great deal.
by Dave
    • Recommended Product
    3 people found this helpful
    Very good sink. It’s easy to install and came on...
    Very good sink. It’s easy to install and came on time. Thank you
    by HomeDepotCustomer
    • Verified Purchase
    Total disappointment
    We thought adding this to our water heater would be a bonus, but it has proven to be a waste of time and money. We cannot get enough hot water to efficiently do laundry or run the dishwater and our showers are little more than lukewarm. It would be great if I liked taking cool showers, unfortunately, I don't.
    by dl40204
      Showing 1-3 of 3 reviews