41
Testing the Sensor Set
If the opposite sensor is now reading higher,
UÊ
the problem is with the sensor(s). Replace the
sensor set.
*
If you wait more than 2 minutes after plugging the
sensors back in, heating may start (even outside a filter
in Economy or Sleep mode) due to a stray Cd/CLd/COLD
WATER condition usually detected when sensors are
being plugged in while the system is running.
7. If there is a message indicating an open or faulty sensor:
Unplug the sensor set (but leave the original sensors
UÊ
in the heater) and plug in the test sensor set. Put
both sensors into the same cup of warm water
(ideally above the set temperature, so the spa won't
try to heat during this test, as there is no heater
protection during this test) and verify that they read
the same temperature (within 0.5°C/ 1°F).
If the problem is solved, replace the sensor set.
UÊ
If the problem is not solved, do not replace the
sensor set.
Plug in the original sensor set to verify that there is
UÊ
not a connection problem.
If the problem continues after following the above
UÊ
steps, then replace the circuit board.
Check sensor wires for cracks or damage that may
1.
indicate the presence of a rodent.
Inspect the connections of both sensors on the circuit
2.
board. The plugs must be clean.
If the sensors are not totally failing but are showing
3.
excessive (1.0°C/2.0°F or more) difference between the
two sensors when not heating (a possible cause of Sn/
SnS/SENSOR SYNC, HL/HFL/HTR FLOW LOW, and LF/
LOW/FLOW/messages), do the following: Note which
sensor is reading consistently higher (A vs B or t vs H).
4. Unplug the two sensors from the circuit board and
exchange their positions (i.e., plug the one that was in
the “Sen. A” jack into the “Sen. B” jack and vice versa).
5. Press a panel button if any "stray" faults appeared during
the process. (Stray faults are normal when sensors
are unplugged then plugged back in while the system
is running.)
6. Within a minute or so*, see if the same or other sensor
is now reading consistently higher:
If the same sensor (A vs B or t vs H) is reading
UÊ
higher after the sensor interchange, the problem is
on the circuit board. Replace the circuit board.
