Service Alert Summary:
Field is reporting SOV is bypassing due to not fully shifting when running Compressor 2 in cooling on dual compressor heat pump with running version 8 or lower firmware and controlled by thermostat. In version 7.02, the compressor staging sequence was changed to start Compressor1 on the cooling call to generated enough differential pressure across the SOV to force it to completely shift. Subsequent cooling cycles will start Compressor 2 as the SOV is supposed to stay energized. It has been found that with W1/O and G energized together, the unit Heat Cool Mode switches to FAN ONLY causing the SOV to drop from Symbio 700 when the cooling cycles ends, this would require Compressor 1 to start again on the next cooling cycle and it does not per sequence.
What are known Diagnostics or Symptoms:
Poor cooling operation while running Compressor 2
Potential overheating compressor
Product Family
Precedent
Model Prefix(s) & Configuration details
- WS/HJ072-300
- DS/HJ072-300
- WS/HK072-300
- DS/HK072-300
Ship Date range
All, applies to Symbio 700 firmware v8 or lower
Serial range
All, applies to Symbio 700 firmware v8 or lower
What actions can I take now:
- Issue was resolved in V9.00.0007 firmware, update firmware to the latest available version → Symbio™ 700 - Firmware Update for Unit Controller Module
Is there a related published service bulletin for this issue?
- At this time, we do not expect any bulletin will be published.
Are WMS(Warranty Management System) claims allowed for this issue?
- Warranty / Concession claims may be allowed.
Does the above information indicate the final resolution?
- No, final resolution has not been confirmed.
Internal Admin Use/Info only:
Logged Defect #373431
Zendesk Problem Ticket #3184039
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