4.F Service function 4.F - trap filling routine

What the display is showing

Controls the routine that fills the condensate trap after installation or a long shutdown, during which the display alternates a symbol with the supply temperature. Values include 01 trap filling at lowest output and 02 trap filling at set minimum output. Only switch it off for servicing and turn it back on afterwards.

Applies to: Greenstar ZBR/ZWB 21-42-3A wall-hung boilers and ZWB 28-42-3A combis

What to do

1. Open service functions with the service button, scroll with the key pad lock / ECO buttons
2. Select 4.F and choose the sequence

Models that show this code

4 models in Bosch Greenstar

Other codes on the same units

• 000-199 Supply temperature readout
• 2.C Service function 2.C - purging function
• 2.F Service function 2.F - temporary test operating mode
• 4.E Service function 4.E - appliance type detected
• 5.A Service function 5.A - reset service-due indication
• 6.A Service function 6.A - latest fault code
• 6.C Service function 6.C - target supply temperature from outdoor reset
• 6.b Service function 6.b - room control voltage at terminal 2