Daikin Altherma fault E3-00
Outdoor unit: actuation of high pressure switch
Heat pumpWhat it means
High pressure switch opens due to measured pressure above high pressure switch operating point. Also triggers on high pressure control (measured pressure just below high pressure switch operating point) occurring 16 times within 300 minutes.
Likely causes
- Closed stop valve in the refrigerant circuit
- Faulty refrigerant pressure sensor
- High pressure switch confirmed faulty during checking procedure
- Refrigerant overcharge
- Non-condensables and/or humidity in the refrigerant circuit
- Clogged refrigerant circuit
- Faulty outdoor unit fan motor
- Poor water flow through high pressure side plate heat exchanger
- Incorrect refrigerant charge
Where to start
- Check that all stop valves of the refrigerant circuit are open
- Perform a check of the refrigerant pressure sensor
- Perform a check of the high pressure switch
The full answer, free
- 15 more checks in order
- The readings and component tests from the manual
- How to put it right, step by step
- The manual page for this fault (page 37), right under the answer
Safety: Isolate the outdoor unit and any backup heater, and give the inverter capacitors time to discharge before you open the electrics. Anything on the refrigerant circuit needs F-gas certification.
From the Daikin manual for the Altherma. Check the model on the data plate before you order parts.
Other Daikin Altherma fault codes
- 4-02Incorrect setting of space heating OFF temperature
- 7HFlow error (minimum flow rate not reached)
- 7H-01Water flow problem
- 7H-04Water flow problem during domestic hot water production
- 7H-05Water flow problem during heating/sampling
- 7H-06Water flow during cooling/defrost
- 7H-07Water flow problem. pump de-blocking active
- 7H-XXWater flow or volume too low
- 80-00Inlet water thermistor abnormality
- 81-00Outlet water thermistor abnormality
- 81-01Mixed water thermistor abnormality
- 89-01Heat exchanger frozen
- 89-02Heat exchanger frozen
- 89-03Heat exchanger frozen
- 8F-00Abnormal increase outlet water temperature (domestic hot water)
- 8H-00Abnormal increase outlet water temperature
- 8H-01Overheating mixed water circuit
- 8H-02Overheating mixed water circuit (thermostat)
- 8H-03Safety thermostat circuit open with jumper removed
- A1-00Zero cross detection problem
- A5-00Outdoor unit: high pressure peak cut / freeze protection problem
- AA-01Backup heater overheated
- AA-02External backup heater overheated
- AC-00Booster heater overheated