STIEBEL ELTRON DHB-E 21 Si

Questions and Answers

U
uclarkAug 11, 2025
How to fix a STIEBEL ELTRON DHB-E 21 Si Water Heater when the heating system won't start?
- K
  katherinethomasAug 11, 2025
  If the heating system inside your STIEBEL ELTRON DHB-E ... Si electronic water heater won't start even when the hot water valve is fully open, try the following: * Check the fuses in your fuse box. * Clean and/or descale percolators in the valves or shower heads, because the start-up volume required to start the heater may not have been reached. * If the heating system is faulty, test the heater and replace it if necessary.
M
Matthew Wright DVMAug 16, 2025
Why does my STIEBEL ELTRON DHB-E 21 Si Water Heater have no hot water with a flow rate over 3 l/min?
- C
  Christopher SanchezAug 16, 2025
  If you have no hot water from your STIEBEL ELTRON Water Heater and the flow rate is greater than 3 l/min, several issues could be the cause: * A faulty PCB, in which case you should test the PCB and replace if necessary. * The high limit safety cut-out (STB) tripped or cable break, so check the high limit safety cut-out and replace if necessary. * A faulty heating system, so test the heating system resistance and replace if necessary.
K
Kevin ChangAug 22, 2025
What causes no hot water in my STIEBEL ELTRON DHB-E 21 Si Water Heater when the flow rate is high?
- M
  Melissa SchultzAug 23, 2025
  If you have no hot water from your STIEBEL ELTRON Water Heater and the flow rate is greater than 3 l/min, possible causes include: * Cold water supply temperature exceeding 35 °C: Reduce the temperature of the cold water supply to the equipment. * Flow rate exceeding 25 l/min: Reduce the flow rate to the equipment. * Cold water sensor fault: Test the PCB, replace if necessary.
J
Jeffrey StephensonAug 28, 2025
How to troubleshoot a STIEBEL ELTRON Water Heater with no 'traffic light' display?
- B
  Billy KnightAug 28, 2025
  If your STIEBEL ELTRON Water Heater isn't displaying the 'traffic light', it could be due to: * The safety pressure limiter AP 3 has tripped: Remove the cause of the fault (e.g., faulty pressure washer). Rinse the heating-system of the unit to avoid over-heating. Press the button on the safety pressure limiter only after isolating the equipment from the electrical supply. * A faulty PCB: Test the PCB and replace it if necessary.
E
Emily AnthonySep 4, 2025
What to do if the flow rate is too low in my STIEBEL ELTRON Water Heater?
- A
  Alexandra YatesSep 4, 2025
  If the flow rate of your STIEBEL ELTRON Water Heater is too low, it might be due to: * Scaled up shower head/percolators: Descale and replace if necessary. * Contamination: Clean the strainer.