Stiebel Eltron · Accelera 220 E / 300 E (earlier manual edition)
Stiebel Eltron Accelera 220 E / 300 E (earlier manual edition) error code 4
What it means
The integral sensor has failed. The mixed water display will not show the correct amount but the appliance will continue to work properly.
How it shows: Service (wrench) symbol continuously illuminated
What Stiebel Eltron says to do
Call Stiebel Eltron for more information if this error occurs.
Last checked 2026-10-03.
Safety first
- WARNING Electrocution: Do not insert objects through the grille into the interior of the appliance. Never spray the appliance with water. Never spray water into the appliance. (pg. 15)
- WARNING Injury: Maintenance work, such as checking the electrical safety, must only be carried out by a qualified contractor. (pg. 15)
From the manufacturer's manual for this series.
The same code on other models
Codes mean different things on different heaters. Match the series to the model number on your rating label.
- Bradford White AeroTherm Series G2: 4
- LG Inverter heat pump (2020 manual): 4
- LG Inverter heat pump APHWC501M / 801M (2024–2025 manuals): 4
- Stiebel Eltron Accelera 220 E / 300 E: 4