The Bosch Tronic TR6100C-18 Electric Tankless Water Heater, part number 7738007420, is an 18-kilowatt whole-house electric tankless water heater designed to deliver continuous on-demand hot water for a one-bathroom residential installation, providing a tank replacement solution that eliminates standby heat loss and conserves installation space while delivering hot water at 3.51 gallons per minute at a 77°F temperature rise.
The TR6100C-18 operates at 95% thermal efficiency with a UEF of 0.94 and features thermostatic modulation that maintains a constant output water temperature within the adjustable range of 86 to 125°F regardless of variations in incoming water temperature or flow demand.
Three separate heating circuits — each requiring a dedicated double-pole 30-amp breaker at 240 volts with 10 AWG minimum wire — power the unit's heating elements, and a ¾-inch MNPT connection on both the cold water inlet and hot water outlet accommodates standard residential plumbing supply lines for straightforward tank replacement installations. The unit must be installed with the plumbing connections facing down toward the floor — any other orientation may result in poor operation or damage to the product.
What's Included: Bosch Tronic TR6100C-18 electric tankless water heater unit with mounting hardware. Three dedicated 240-volt double-pole 30-amp hardwired circuits using 10 AWG minimum wire per circuit and all plumbing connections are not included and must be provided as part of the installation by a licensed electrician and plumber. Teflon tape must be used to seal all pipe connections — pipe dope must never be used as it can damage the flow switch and internal heating elements.
Installation Limits: The TR6100C-18 requires three separate dedicated 240-volt double-pole 30-amp hardwired circuits, each wired with 10 AWG minimum wire, and must be hardwired only — no plug-in connection is permitted. The unit must be installed with the plumbing connections facing down toward the floor at all times.
Water shut-off valves are strongly recommended at both inlet and outlet connections. Minimum activation flow is 0.5 gpm and minimum working water pressure is 7 psi. Customers replacing a Bosch WH17, RP17, or AE-115 must update the existing electrical installation from the two 40-amp double-pole breakers those models required to the three 30-amp double-pole breakers required by the TR6100C-18 — this electrical update is mandatory and not optional.
Compatibility: The Bosch Tronic TR6100C-18 (part number 7738007420) is a whole-house one-bathroom electric tankless water heater and the lower-kilowatt model in the Bosch Tronic 6100C series available at RuralEnergy.com. The companion model available in the same series at RuralEnergy.com is the TR6100C-27 (part number 7738007421) at 27 kilowatts, rated for one to two bathrooms. The TR6100C-18 is a close functional replacement for the Bosch WH17, RP17, and AE-115, subject to the mandatory electrical circuit update described in the Installation Limits section above.
