ECO button lit ECO button lit - economy / alternating mode

What the display is showing

The ECO button light shows the mode chosen. On a combi (ZWB) lit means Economy mode: hot water is only made when a tap is drawn, and a quick open and close of a tap asks for hot water. Not lit is Comfort mode, where the boiler keeps the DHW at temperature. On a heating boiler with a DHW tank (ZBR) lit means alternating operation between heating and tank; not lit is DHW tank priority (default).

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

Models that show this code

4 models in Bosch Greenstar

Other codes on the same units

• CC Outdoor temperature sensor not recognised
• DHW setpoint flashing Set DHW temperature flashing on display
• Display off Display dark - appliance switched off
• EA No flame detected
• Emissions test button Emissions test (chimney sweep) button
• FA Flame detected after gas shut off
• Fd Reset button pressed by mistake
• Key pad lock button Key pad lock