High burn rate
If the stove appears to have a high burn rate when the controls are set low or even closed, check that the controls are closing properly (they will not close air-tight).
Also check that the door rope is forming a tight seal when the door is closed, and check the rope seal around the door glass for any gaps, for this you could perform the Paper test.
The Paper Test
Fold a single sheet of A4 paper in half and close the door against the paper. The door rope should grip the paper so that it doesn’t fall away. If the paper falls out then the rope seal will potentially need replacing.