The figures we quote in our instructions are in mm Water Gauge.
Quoted limits are either: Millimetres Water Gauge – Inch Water Gauge – Pascals – Millibar
Minimum Draught: 1.2 mm WG = 0.047 ”WG = 11.8 Pa = 0.12mbar
Maximum Draught: 2.5 mm WG = 0.098 “WG = 24.5 Pa = 0.25mbar