23
M720 pH/ORP Controller Owner’s Manual
C. Maintenance
1. Winterizing (extended shutdowns or colder climates)
a. Turn off the M720 controller and shut off main power to
controller.
b. Gently remove the ph and ORP sensors from the flow
cell. Fill the provided protective caps (removed during
installation) with water and re-install onto each sensor, and
store in a warm, secure location.
c. Drain the water from the flow cell.
2. Cleaning the sensor tips
Note: It is important to keep the sensor tips clean in order to
ensure accurate readings.
a. Sensor tips should be cleaned every 1 to 3 months for
commercial pools and spas, and every 3 to 6 months
for residential pools and spas. Determine the necessary
frequency by comparing the readings before and after the
cleaning. Identical readings mean that the cleaning time
can be extended.
b. Turn off the M720 controller.
c. Close the right and left valves at the bottom of the flow
cell.
d. Loosen the nut fitting on the sensor and gently remove it
from the flow cell.
e. Swirl the sensor tip for 5 seconds in Muriatic acid or white
vinegar and rinse with water.
Note: Do not touch or brush
the sensor tip.
f.
For commercial pools and spas:
For every 3rd cleaning,
swirl the sensor tip in a liquid soap and water solution.
Rinse with water.
g. Gently re-insert the sensor into the flow cell and hand
tighten the nut fitting.