Draining The Heating System - Wolf FGB-K Series Installation And Maintenance Instructions For Contractors

Draining the heating system:

Operating mode button
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20. Draining the heating system
• Switch the boiler OFF at the control unit.
Press the operating mode button until "OFF" shows in the display.
The boiler then enters standby mode.
If the appliance is connected to a BM-2, the operating mode key is
disabled. The BM-2 takes over this function.
• Isolate the boiler from the power supply at the on-site appliance fuse.
• Close the gas ball valve.
• Allow the temperature in the heating circuit to cool to at least 40 °C.
(Risk of scalding!)
• Safeguard the heating system against accidental reconnection to the
power supply.
• Open the drain valve (boiler drain & fill valve, on site).
• Open the air vent valves on the radiators.
• Drain the heating water.
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