Humboldt H-1394 Deluxe Water Baths - Manual (Page 6)

Switching from °F to °C
Humboldt 120V Deluxe Water Baths come set to °F and 220V models come
set to °C for the controller. If you desire to change this setting, hold the up and
down arrow buttons in at the same time and hold for 3 seconds. The controller
will switch to this view: Figure #3:
then push the up arrow button to change the number 2 to number 5
Now, push the blue button 4 times, or until you see the C _ F on the display,
then push the up or down arrow buttons to toggle between C and F. Then push
the infinity button 2 times to return to the temperaure display screen, Figure
#2. Then, once again hold the up and down arrow buttons in for 3 seconds. The
controller will switch to this view: Figure #3. Push down arrow to change the
number 2 to a 5, which will lock the unit's controls again. Then push the infinity
button 2 times to return to the normal view, Figure #2.
Figure #3
Figure #4