Lincat IH21 Installation, Operating And Servicing Instructions page 6

It is normal for induction generators to make buzzing, whistling and clicking noises,
especially on lower power settings.
If the ceramic glass surface is cracked, immediately disconnect the appliance
from the supply.
Use
Connect to the mains supply and switch on via the On/Off switch located on the
base of the appliance (see Fig 4). The green neon will illuminate and the cooling
fan will be heard.
Control knob functions
Fig 2
A Off. B Low temperature hold. C Level 1. D Level 2. E Hob indicator. F Level 3.
G Level 4. H Level 5. I Level 6. J Level 7. K Level 8. L Level 9. M Power boost.
N Automatic heat up and control lock.
Warning: Do not move the control knob directly between Power Boost and
Automatic Heat Up.
IS 519 ECN 3681 Page 6 of 12