Maybe this an apples to oranges comparision...
I also have a Belles 20A, plugged it back in, power swich off and there is a faint glow on the filaments. When powered on, the glow reaches the intensity that I see with the 21A powered off.
I also have a Belles 20A, plugged it back in, power swich off and there is a faint glow on the filaments. When powered on, the glow reaches the intensity that I see with the 21A powered off.