If the gauge moves after depressing the steam switch to on, then the steam wand hole and frothing aid should be cleaned.
If the gauge needle does not move at all but the machine does get hot, your machine probably has limescale in the capillary tube to the gauge. The gauge needs to be replaced as descaling usually does not correct this condition.
If gauge needle moves for coffee mode, but not steam mode, then the steam thermostat may be defective and needs to be replaced.
If you have to get more water in the boiler through coffee mode for only 1 cup of milk steaming, your machine may have limescale on the OPV or if a Dream UP on the 3 way solenoid valve. The valve may be held open by the limescale and all the steam (and related water) is draining from the boiler, which gives you less water for steam. The machine should be thoroughly descaled.
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