Flow Rate; Operation Guide - Black & Decker BD-24-DWH Mode D'emploi

9. Flow Rate

The chart below indicates maximum temperature rise for a given flow rate
Item #
BD-24-DWH
BD-27-DWH

10. Operation Guide

Operating your new tankless water heater is similar to using any traditional water heating system.
However, it is essential that you carefully read all setup procedures, operating instructions and
tips to ensure the maximum performance and energy savings from your new water heater. We
recommend that all members of the household read these General Operating Instructions.
This electric water heater is designed to supply hot water. The unit contains heating elements within,
capable of heating water quickly on-demand for as long as you need it. Unlike a conventional tank
storage water heater, this unit is a tankless water heater that does not store hot water. However,
once you begin using the system, you will understand it works like a conventional tank system.
Tankless system delivers hot water instantaneously on demand. Since a tankless system does not
waste energy continually when heating water, i.e. idly sitting and losing heat in a storage tank, it
provides significant energy savings than a conventional water heater.
With your new system, as soon as you turn on the hot water faucet, the demand for hot water is
detected by a flow sensor, and the high-power heating elements are activated. Sensors continually
monitor the water flow rate and measured the incoming and outgoing water temperature. Data is
transmitted to the system logic controls, which determines the exact amount of power required by
heating elements to heat the water to your desired temperature.
It is essential to keep in mind that all tankless water heaters are subject to a maximum flow rate. If
this flow rate is exceeded, the heater will not be capable of sufficiently heating water.
Also keep in mind that conventional tank heaters are set to high temperatures to prevent running
out of hot water quickly, and thus a large amount of cold water needs to be mixed in to reach a
comfortable level for washing and showering. Since this unit heats water on demand, it is designed
to heat to a lower temperature. This means you only need to mix in a small amount of cold water
or none at all.
Your hot water supply may also be affected by the incoming water temperatures as the season
differs. During winter, if the incoming water temperature is frigid, you might not be able to run
multiple hot water outlets at the same time as compared to the summer. However, you can run
showers back-to-back without having to wait for the water to heat.
Water Quality: One of the things which should be taken into consideration when installing and
maintaining the water heater is the quality of water. Water conditions outside the recommended
12
levels outlined below are not permitted and can damage the water heater. We reserve the right to
INLET GROUND WATER TEMP
kW 30°F
24 5.2
27 5.4
Based on 105°F Output Water Temp
40°F 50°F
3.95 3.52
4.15 3.65
60°F 70°F
3.3 2.4
3.4 2.7