Haier AW07LC2VHA Technical Overview page 51

Cassette Unit Testing Procedures: Communication Circuit, Condensate Pump & Float Switch
Testing Communication Circuit
If an Error E7 occurs, perform the following test to determine if
the indoor control board is functioning properly to send data to
the outdoor unit.
Perform this test with the unit powered and all wiring connected
between indoor and outdoor unit.
Make sure all wiring between the indoor and outdoor unit are
correct. There should no splices between the indoor and outdoor
unit wiring connecting terminals 1 or 3. Make sure wiring is
correct, before performing this test.
1. Measure the DC voltage between terminals 1 and 3 on
the indoor terminal block.
2. The voltage should fluctuate between 8VDC and 23VDC. The fluctuating signal indicates a good communication path.
3. If the voltage does not fluctuate, and the wiring is good, the indoor board is defective.
Test Condensate Pump and Associated Float Switch
If the internal condensate pump does not operate, the pump may be bad or the float switch may be defective. Perform the
following test:
Float Switch and Condensate Pump
1. Access the electrical control box.
2. Unplug the float switch from the circuit board. Plug CN-18.
3. The pump should start.
4. If the pump does not start, check for voltage to the pump at connector CN-9. There should be 230 Volts AC to the
pump. If there is not, the circuit board is defective. If there is proper voltage to the pump, either the pump or associated
pump wiring is defective.
Disconnect Float
Switch
CASSETTE UNIT TECHNICAL OVERVIEW
TESTING
Check E7
Disconnect Condensate
Pump
PAGE 51