Bosch has been the premier manufacturer of water heating and plumbing supplies, being a household name for over 125 years. Carried with the prestige is also the continuous dedication to innovation, inspiring Bosch to evolve for greater efficiency and greater quality. Bosch has even developed the exclusive use of upward transfer of motion heat exchanger, thus increasing the longevity of their products as well as promoting efficient use. With the many years of experience, Bosch’s products exude the name and the quality.
The Bosch 660 EF NG is the compact tankless water heater that features a non-condensing heat exchanger. This tankless water heater utilizes natural gas, and is one of the most compact in the industry. The 660EFNG has a heating element that produces up to 140,000 BTUs per hour, providing continuous hot water to wherever the application may need. With 6.6 gallons per minute capacity at 35°F rise, this unit had the heating element to supply a shower and sink simultaneously without the loss of hot water. The heating power of this unit does not compromise its energy consumption; the unit’s energy factor is rated at 0.82 with a thermal efficiency rating of 83%. The Bosch 660 EF NG can be used in both residential and commercial applications with its maximum temperature of 160°F.
For greater versatility, the 660EFNG can be used in recirculation, thermal and solar applications as well. This unit is suitable to function in altitudes up to 4,500 ft. All these great features are backed by Bosch’s 15 year warranty, an industry standard. In addition, the product life further exceeds 20 years and all of the water heater’s parts are 100% serviceable. These great features make the Bosch 660 EF NG the last water heater you’ll ever need to buy.
Manufacturer Product Manual (PDF)
• Suitable for indoor use
• 83% thermal efficiency
• 140,000 BTU maximum input
• 6.6 gallons per minute capacity at 35F degree rise
• Minimum activation flow rate of 0.5 gallons per minute
• Patented burner design
• Exclusive safety controls
• Can be used in solar thermal, recirculation applications
• Energy Star Certified
• Energy Star Certified
• Built for durability and serviceability with 15 Year Warranty and 20+ Years Product Life Expectancy
• Condensing/Non-Condensing: Non-Condensing
• Application: Residential or Commercial
• Max Input (BTU): 140,000
• Min Input (BTU): 20,000
• Capacity at 35°F Rise (gpm): 6.6
• Capacity at 55°F Rise (gpm): 4.2
• Intelligent Cascading: No
• Min Flow Rate: 0.50 gpm
• Temp Range (°F): 100 - 140
• Temp Stability (°F): +/- 2
• Default Temp (°F): 120
• Energy Factor: .82
• Thermal Efficiency: 83%
• Installation Options: Indoor
• Dimensions (w x h x d): 14" x 20 1/2" x 7"
• Weight (lbs.): 36
• Inlet Connection: 3/4" NPT
• Outlet Connection: 3/4" NPT
• Gas Connection: 3/4" NPT
• Min NG Pressure: 4" WC
• Max Water Pressure: 150 psi
• Min Water Pressure: 30 psi
• Condensing Heat Exchanger: N/A
• Venting Options: Stainless Steel
• Vent Maximum Run: 35'
• Energy Star Rated: Yes