I copied this awhile back, never tried it, hope it works for you:
Thermostats at OKW are one of the easiest to override. Press and hold the F/C button on the left side of the thermostat. After 2-3 seconds bp will show on the display. The bypass will last for 24 hours so you need to do it every day. Pressing the F/C button will also change the display from Fahrenheit to Celsius. Just press it again to switch it back to whichever you prefer.