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9 DIAGNOSTICS AND FAULT CODES
Alpha SolarSmart 90 - Diagnostics and Fault Codes
Codes 71, 72 and 80 will stop the solar system working:
The cause must be rectified before the system will
operate. When the cause has been rectified the system will start by itself.
Code 71
Collector sensor fault
Temperature of the collector is below -40°C or above 250°C.
Check the collector sensor: does it operate (check sensor resistance in table on next
page).
Sensor cable damaged or short circuited.
Sensor is faulty.
Code 72
Upper cylinder sensor fault
Temperature of the cylinder is below 0°C or above 100°C.
Check the upper cylinder sensor: does it operate (check sensor resistance in table on
next page).
Sensor cable damaged or short circuited.
Sensor is faulty.
Code 80
Lower cylinder sensor fault
Temperature of the cylinder is below 0°C or above 100°C.
Check the lower cylinder sensor: does it operate (check sensor resistance in Section
7.3).
Sensor cable damaged or short circuited.
Sensor is faulty.
Code 77 is the only code displayed that is not actually a fault:
The code will disapear if the button is pressed.
Code 77
The system is not turned on
The control has not been operating for 30 days.
Check the collector sensor and the lower cylinder sensor, do they operate (check
sensor resistance in Section 7.3).
Codes 74 and 75 will lock the solar system:
The cause must be rectified before the system will operate. When the
cause has been rectified the system control can be reset by pressing the button.
Code 74
No circulation in the
collector
Check water level in drain back unit.
Check the difference in height between the drain back unit pump and the upper most
side of the collector. This can be a maximum of 3 metres.
Check the collector sensor and the lower cylinder sensor, do they operate (check
sensor resistance in Section 7.3).
Check the collector tubes, are they blocked with dirt? Is the decline of the pipes within
the 40 mm per metre requirement.
Check the electrical connection and operation of the drain back unit pump and the
cylinder pump.
Code 75
Collector temperature too
high
After 5 minutes the collector temperature is still too high (above 130°C) with the drain
back unit pump operating.
Check the level of water in the drain back unit. Refer to filling procedure in Section
5.2.
Check the difference in height between the drain back unit pump and the upper most
side of the collector. This can be a maximum of 3 metres.
Check the collector sensor and the lower cylinder sensor, do they operate (check
sensor resistance in Section 7.3).
Check the collector tubes, are they blocked with dirt? Is the decline of the pipes within
the 40 mm per metre requirement.
Check the electrical connection and operation of the drain back unit pump and the
cylinder pump.
9.1
FAULT CODES
The solar system is fully controlled by the electronic control on the cylinder. Fault codes will be displayed at the cylinder
by means of a flashing fault code (71 to 80). The following codes can be displayed.
