Bug fixes

- Increased fill timeout to 120 minutes to allow enough time
- Increased detection range for float valve as it wasn’t detecting
properly (yet it worked with V2.1 without change - unsure why this code
has trouble reading it)

Known Bugs:
+ Read temperatures sometimes fluctuate by up to 1 degree without
cause, yet the sensor read occurs correctly. Possibly due to
fluctuations in voltage on the 1Wire bus (which may explain the float
value issue). Possibly the 1Wire library thinks one or more sensors is
in parasitic mode.