Can I use a Stiebel Eltron Tempra tankless water
heater with my radiant floor heating system?
The manufacturer does not recommend using the Stiebel Eltron Tempra Trend or Tempra Plus Series for closed-loop radiant heating applications.
If you are looking to use an electric tankless water heater for radiant heating, Stiebel Eltron does have a purpose built unit that is similar to the Tempra for use in radient heating applicatoins. The HydroShark® series of electric modulating micro-boilers are designed specifically for radiant floor applications. The HydroShark® features a higher boiler flow rate, no minimum activation flow rate, heavy duty controller triacs, and are manufactured to UL 834 standards.
More information on the HydroShark® systems can be found at: