Error Code 2000 - Mitsubishi Electric PQHY-P72TYHMU-A Service Handbook

[ IX Troubleshooting ]
1. Error Code
2000
Pump interlock error
2. Error definition and error detection method
1) This error is detected by the pump interlock circuit (TB8 3-4).
2) If it is detected that the pump interlock circuit (TB8 3-4) is open (first detection) during operation or immediately before startup,
the heat source unit stops and goes into the 10-minute restart delay mode.
3) If the pump interlock circuit (TB8 3-4) has remained open for continuous 10 minutes (second detection) since the first stoppage
of the heat source unit, the unit will make an abnormal stop, and the error code "2000" appears on the LED.
4) For the 10 minutes from the time the heat source stopped is considered a preliminary error, and it is indicated on the LED.
5) This error is indicated on the LED only when Dip switch SW2-8 on the control board of the heat source unit is set to OFF.
3. Cause, check method and remedy
(1) Heat source water circulation pump fault
(2) Broken wire
(3) Loose connectors or contact failure
(4) Interlock signal input circuit fault on the relay board
(5) Interlock signal input circuit fault on the control
board
HWE09080
Cause Check method and remedy
Operate the pump, and check for proper operation.
Check the field wiring for proper installation and conduc-
tion.
Check the connectors for proper connection.
- 235 - GB