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Gas Tankless Water Heaters
Therm 660 EF
Energy Efficient
Product Overview
Eligible for up to $300 Federal Tax Credit
The Therm 660 EF is compact enough to install virtually anywhere. But don’t let the size fool you. This model is loaded with features including freeze protection and built-in high temperature capability (160F) for commercial applications.
Features & Benefits
- Super compact 14” x 21” x 7” size
- 83%+ thermal efficiency
- 140,000 BTU maximum input
- 6.6 gallons per minute capacity at 35F degree rise
- Suitable for residential or commercial applications
- Minimum activation flow rate of 0.5 gallons per minute
- Electronic ignition
- Built in freeze protection
- Vents vertically or horizontally with 3” or 4” stainless steel
- Can be used in tank loading, recirculation, radiant floor and space heating applications
- Available in NG and LP models
Warranty
2 year limited warranty on heat exchanger if the high temperature kit is installed
5 year limited warranty on all other parts
Bosch Warranty Details
| Therm 660 EF | Specifications |
|---|---|
| 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 | 0.5 gpm |
| Temp Range (°F) | 100 - 160 |
| 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 20½" x 7" |
| Weight (lbs.) | 36 |
| Inlet Connection | ¾" NPT |
| Outlet Connection | ¾" NPT |
| Gas Connection | ¾" NPT |
| Max Water Pressure | 150 psi |
| Min Water Pressure | 30 psi |
| Min NG Presure | 4" WC |
| Condensing Heat Exchanger | n/a |
| Venting Options | Stainless Steel |
| Vent Maximun Run | 35' |
| Energy Star Rated | Yes |
