811
Hot water heating: thermal disinfection failed
Worcester Bosch Greenstar 4000 (from May 2021)
Remedy
▶ If water is being drawn constantly, take action to stop this.
▶ Position the DHW temperature sensor correctly.
▶ Check that there is contact between the DHW cylinder temperature sensor and the cylinder.
▶ Vent the cylinder circuit.
▶ Set DHW heating to "priority".
▶ Check plate heat exchanger for calcification.
▶ Check sizing of DHW circulation line and heat loss.
This code also applies to: