Instantaneous water heater

BOSCH TR8501i 15/18/21 DESOAB Electric Tankless Water Heater, 21 kW, 400 V

Full-colour touch display with temperature setting accurate to 1 °C.

The Bosch TR8501i 15/18/21 DESOAB tankless water heater from the Tronic 8500i range heats water on demand, with no storage cylinder. It runs on a three-phase 400 V supply and is pressure-rated, so it can feed more than one tap point in the home. Wall-mounted in a vertical position, with the electrical supply entering from the top or through either of the two lower cable inlets.

Switchable output: 15, 18 or 21 kW

The heater is set at installation to match the available electrical capacity and the household's hot water demand. At the top setting the flow rate reaches 11.6 l/min, enough for a shower and a basin at the same time.

Colour touch display with five buttons

You enter the target temperature in degrees and the electronics hold it to within 1 °C when pressure or flow changes. Control is fully electronic and the glass front panel wipes clean with a damp cloth.

AquaStop protection and built-in Wi-Fi

AquaStop shuts off the water if a leak is detected inside the appliance. The Wi-Fi module is built in at the factory, so no extra accessory is needed to connect it to your home network.

Clickfix plus mounting in three steps

The transparent back plate reveals existing wall holes so they can be reused when replacing an older unit. Colour-coded connection points guide the installer through the plumbing, and the heater can also be run downstream of a solar system.