What's the difference between the Stiebel Eltron Tempra & Tempra Plus models?
The difference between the Stiebel Eltron Tempra and Tempra Plus tankless water heaters comes down to two things. The Tempra Plus series have a digital temperature display and use dynamic advanced flow control technology. The basic Tempra or Tempra B series do not have these features.
Tempra Plus Digital Display
The Stiebel Eltron Tempra Series of electric tankless water heaters has a knob on the front of the unit which is used to set the temperature. Approximate water temperatures are clearly marked around the exterior of the knob in both fahrenheit and celcius.
The Stiebel Eltron Tempra Plus electric tankless water heaters also has a knob similar to that the the basic Tempra systems. Instead of having the temperature marks around the knob, it displays the temperature on an LCD digital display.
Tempra Plus Dynamic Advanced Flow Control
While both the Tempra and Tempra Plus units are thermostatically controlled only the Tempra Plus series offers dynamic advanced flow control. This is a valve inside the unit which will limit the flow rate of hot water if you attempt to draw more water than the unit can heat to the temperature you have it set to.
Dynamic Advanced Flow Control Example
If you attempt to get a 50°F temperature rise at 4 gallons per minute, the Tempra 24 and Tempra 24 Plus will react differently. Both units can only provide 3.3 gallons per minute with a 50°F. The Tempra 24 will provide 4 gallons per minute with only a 42°F temperature rise. The Tempra 24 Plus will reduce the flow down to 3.3 gallons per minute and continue to provide a 50°F temperature rise.