Tankless Water Heater 520 HN

888 718-8448
Tankless Water Heater 520 HN

Tankless Water Heater 520 HN

The Therm 520 HN incorporates an evolutionary hydro-power ignition system which allows this tankless water heater to work without a standing pilot, grid connection or battery! A small turbine inside the water heater uses the energy from the flowing water to ignite the burner.

The modulating gas valve then maintains a constant temperature at varying flow rates. This innovative technology, patented by Bosch, makes this an ideal product for installations without access to electricity or regions prone to inclement weather and power outages.

Therm 520 HN Specifications:

  • Non-Condensing
  • Residential Application
  • Max Input (BTU) 117,000
  • Min Input (BTU) 30,735
  • Capacity at 35°F Rise (gpm) 5.2
  • Capacity at 55°F Rise (gpm) 3.4
  • Min Flow Rate 0.6 gpm
  • Energy Factor 0.78
  • Thermal Efficiency 80%
  • Installation Indoor
  • Dimensions (w x h x d) 18½" x 36¾" x 10½"
  • Weight (lbs.) 35
  • Inlet Connection ½" NPT
  • Outlet Connection ½" NPT
  • Gas Connection ¾" NPT
  • Max Water Pressure 150 psi
  • Min Water Pressure 30 psi
  • Min NG Presure 5.7" WC
  • Venting - Galvanized B-Vent

Features & Benefits:

  • Patented Hydro-power ignition requires no electricity
  • 80% thermal efficiency
  • 117,000 BTU Maximum input
  • 5.3 gallons per minute apacity at 35F degree rise
  • Endless hot water for up to 2 applications at a time
  • Minimum activation flow rate of 0.6 gallons per minute
  • High to low temperature control
  • Vents with galvanized B vent – natural draft
  • Built for durability and serviceability with 15-year warranty and 20+ year life expectancy


  • 15 year limited warranty on heat exchanger
  • 2 year warranty on all other parts


Get a quote



  • "This company is very honest, fair and professional..."

    I am more than satisfied with Richair Comfort Solutions' workmanship and business practices. This company is very honest, fair and professional. They work clean and answered all our questions clearly and effectively. Highly recommend to all!

    Nick C.
    New York, NY

  • "Richair Comfort Solutions were very professional and knowledgeable..."

    I contacted several companies for an estimate to install new ductless air conditioning system. I found Richair Comfort Solutions; they were very professional and knowledgeable. Their product specialist spent a lot of time explaining the differences in ductless systems available today. I took their advice and I am really happy with my new ductless system.

    Mark, Fort Lee, NJ 07024

  • "Thanks for the great job!"

    Thanks for the great job and for being meticulous throughout with everything!

    Ira S., Little Neck, NY