Danfoss A80 Error Code
Condenser block alarm — manual reset required
Source: Danfoss 10/BC194286421698en-001101.pdf
What does Danfoss A80 mean?
On the Danfoss ERC 21X controller, A80 is a condenser-block alarm: the condenser temperature has become too high and a manual reset of the alarm is required. The manual states the block alarm can be reset by setting the r12 main switch off and on again, or by powering the controller down. It is a latched protection that demands attention before the unit resumes normal duty.
Symptoms
- Display alternates between air temperature and the code A80.
- Alarm stays latched and does not clear by itself.
- Cooling capacity is reduced by the overheating condenser.
- Alarm relay is activated.
Common causes
- Severely restricted condenser air flow (heavily blocked coil).
- Failed condenser fan leading to sustained overheating.
- High ambient temperature combined with poor ventilation.
- An earlier A61 condition that escalated to the block threshold.
Ask the AskWhiz AI about Danfoss A80
AskWhiz
online
Diagnostic steps
Read the alarm
Confirm A80 and recognise it as a latched condenser-block alarm needing a manual reset.
Correct the overheating cause
Clean the condenser, confirm the fan runs, and clear any ventilation obstruction so the condenser temperature falls.
Reset the alarm
Set the r12 main switch off and on again, or power the controller down and up, as the manual specifies to reset the block alarm.
Verify normal operation
After reset, confirm A80 does not return and that condenser temperature stays within range under load.
When to call a professional
Because A80 is a latched protection triggered by a serious overheating condition, recurrence after a reset means the root cause is unresolved. A refrigeration technician should measure system pressures, check the fan and charge, and confirm the condenser can reject heat properly. Repeatedly resetting a block alarm without fixing the cause risks compressor damage, so trained diagnosis is warranted before returning the unit to service.
Stop searching through PDFs. Our AI assistant on WhatsApp is trained on official Danfoss documentation and can diagnose this fault code and guide you through the repair in minutes.
5 free questions per bot in your browser — no signup.
Other Danfoss Error Codes
Fault in controller
Cut-out S2 sensor
Short circuited S2 sensor
Cut-out S3 sensor
Short circuited S3 sensor
Fault on signal from Pc (condensing pressure transmitter)
Fault on signal from P0 (evaporating pressure transmitter)
No refrigerant has been selected
Step motor fault (valve output or phase)
Regulation stopped — main switch off (standby mode)
Sair sensor error — air temperature sensor
Def sensor error — S5 evaporator sensor