ESIE13-03
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Part 2. Troubleshooting
4. Component checklist
Page 80
13/05/15
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Version 2.0
Ground source heat pump
5. Measure the voltage on connector X28A: pin 1-3 on PCB A1P; if no 230 VAC is present:
-
check fuse FU1 on PCB A1P, replace if blown,
- replace
PCB
A1P.
6. Measure the voltage on connector X28A: pin 2 and X20A: pin 1 on PCB A1P; if no 230 VAC is present, replace PCBA1P.
7. Using a contact thermometer, measure the temperature at the 3-way valve Domestic Hot Water exit and at the Space Heating
exit; the Domestic Hot Water exit must have the same temperature as the 3-way valve input, the Space Heating exit must have
a much lower temperature.
8. Activate Space Heating.
9. Measure the voltage on connector X28A: pin 2 and X20A: pin 5 on PCB A1P; if no 230 VAC is present, replace PCBA1P.
10. Using a contact thermometer, measure the temperature at the 3-way valve Domestic Hot Water exit and at the Space Heating
exit; the Space Heating exit must have the same temperature as the 3-way valve input, the Domestic Hot Water exit must have
a much lower temperature.
11. If one or both checks above are not OK, remove the 3-way valve motor from the 3-way valve.
12. Set the 3-way valve manually in the Domestic Hot Water position.
13. Using a contact thermometer, measure the temperature at the 3-way valve Domestic Hot Water exit and at the Space Heating
exit; the Domestic Hot Water exit must have the same temperature as the 3-way valve input, the Space Heating exit must have
a much lower temperature.
14. Set the 3-way valve manually in the Space Heating position.
15. Using a contact thermometer, measure the temperature at the 3-way valve Domestic Hot Water exit and at the Space Heating
exit; the Domestic Hot Water exit must have the same temperature as the 3-way valve input, the Space Heating exit must have
a much lower temperature.
16. If one or both checks above are not OK, the 3-way valve body must be replaced, refer to
"Replacing the 3-way valve body" on
17. If both checks above are OK, the 3-way valve motor must be replaced, refer to
"Replacing the 3-way valve motor" on page 125
X28
X20