The Bosch Therm 660EF indoor tankless water heaters require 3" single-wall stainless steel vent pipe and are designed to be vented either through the roof or out the side wall.
The following four models are available for same-day shipping:
- Bosch Therm 660EF-NG (Natural Gas)
- Bosch Therm 660EF-LP (Liquid Propane)
- Bosch Therm 660EFO-NG (Natural Gas)
- Bosch Therm 660EFO-LP (Liquid Propane)
Check out our special discounted pricing as these heaters are available at this reduced pricing while supplies last.
Also consider purchasing the following: