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Testing; Test Condensate Pump And Float Switch; Testing Communication Circuit - Haier 2U18MS2VHB Service Manual

Ductless multi-split heat pump, outdoor/indoor, wall mount - highwall, 2'x2' compact cassette, 3'x3' large cassette, slim duct, mid-static ducted, medium static ducted, console
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Test Condensate Pump and Float Switch

The unit has a built-in condensate pump and water level
safety switch. There are also two optional ports for gravity
drainage. The condensate pump is rated to lift water up to 27
9/16" from the point of discharge.
The unit comes with a grey connection hose with clamp. This
hose is connected to the High ESP Duct unit condensate
discharge hose port. The other end of the hose is sized to
accept 3/4 inch PVC piping.
Recommended condensate piping configurations are shown
If the internal condensate pump does not operate, the pump
may be bad or the float switch may be defective. Perform the
following test:
1. Access the electrical control box.
2. Unplug the float switch from the circuit board.
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3. The pump should start.
4. If the pump does not start, check for voltage at the control

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
2. The voltage should fluctuate between 8VDC and 23VDC.
3. If the voltage does not fluctuate, and the wiring is good,
board pump connection. 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.
indoor terminal block.
The fluctuating signal indicates a good communication
the indoor board is defective.

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