NETZERO (57.2% efficiency) ThermoDrain TDH3620B-DR high performance drain water heat recovery unit + Free shipping*


The TDH3620B-DR is the most popular unit for those seeking the highest efficiency possible and yet, fit in a common basement space.
NETZERO and PASSIVEHOUSE builders use this unit to achieve the highest heat recovery from waste water possible.

TDH3620B-DR  Specifications:

  • 57.2% Efficiency @ 9.5 L/min (2.5 GPM)
  • When showering, a 57.2% efficient unit is designed to preheat incoming cold water from 50 F (10 C) to 78.6 F (26 C) @ 2.5 GPM (9.5 L/min)
  • 3″ inner drain diameter
  • 62.0″ Length (perfect length for typical basements)
  • 10.7 kW Heat Recovery
  • 32.4 lbs
  • Equipped with 2 drain couplings
  • Male 3/4 copper water connections
  • Efficiency verified to CSA B55.1
  • Safety certified to CSA B55.2
  • Download TDH specification sheet


ThermoDrain TDH3620B-DR (57.2% eff) drain water heat recovery

ThermoDrain is an easy and comfortable way to save money and help the environment.

The ThermoDrain TDH3620B-DR series is the latest technology in Drain Water Heat Recovery. Its unique compact design provides high efficiency and an easier
installation. With its exclusive features, the ThermoDrain™ TDH series is simply the best technology available today!

ThermoDrain technology is recommended by the United States Department of Energy, Manitoba Hydro and Hydro Quebec

Code required in all new home construction in Manitoba and Ontario, Canada.

Click Here to view the Specification Sheets

Click here to view Installation guide

ThermoDrain TDH3620B-DR Model benefits/ features

  • Enjoy hot showers with peace of mind for the environment and energy costs
  • Feel the heat by triples your tank hot water heater capacity for showering
  • Built with the thickest and purest copper for safety and longevity
  • Safety first with double third party certifications for potable water and efficiency.
  • Enjoy significant flow increase on tankless hot water heaters.
  • Quick payback, great return on investment
  • Compact design/ lightweight
  • Maximum efficiency per inch / cost
  • Easy and fast DIY installation (Select the TDH3620B-DR-PEX for factory installed PEX fittings)
  • Includes easy to install drain fittings
  • 50% efficient units are capable of preheating cold water from 50 F to 75 F @ 2.5 GPM
  • Low pressure drop
  • Fits onto any 3″ drain piping system
  • Fits into any 3/4″ potable water type piping



drain water heat recovery pricing

Drain water heat recovery benefits