In brief
Fault code A01 on Toshiba Estia (Air/Eau) means: Specific to Estia Air/Water heat pumps, code A01 indicates that the flow controller does not detect sufficient water circulation to transfer heat. Most common cause: Clogged strainer, seized or faulty circulator, closed valves, or air in the circuit. First action: Clean the strainer (mud pot) on the heating return.. Call a registered engineer if the fault returns after basic checks or involves refrigerant work (F-Gas registered engineer required).
According to the Toshiba Estia R32 service manual (page 121), the A01 fault code indicates a water flow fault that can be caused by pipework longer than 12 metres with branches.
A01 • Toshiba • Estia (Air/Eau)
Fault code A01 Toshiba Estia: Water flow fault
Specific to Estia Air/Water heat pumps, code A01 indicates that the flow controller does not detect sufficient water circulation to transfer heat.
Source: Toshiba Estia Series 5 Service Manual
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What does fault code A01 on Toshiba mean?
Specific to Estia Air/Water heat pumps, code A01 indicates that the flow controller does not detect sufficient water circulation to transfer heat.
Clogged strainer, seized or faulty circulator, closed valves, or air in the circuit.
Symptômes
- The heat pump does not heat
- Immediate compressor shutdown
- Flow indicator illuminated (if present)
Diagnostic
1. Hydraulic check
- Clean the strainer (mud pot) on the heating return.
- Check that the valves are open.
2. Circulator check
- Free the circulator if seized.
- Bleed air via automatic air vents.
How to reset fault code A01 on Toshiba?
Restore flow (clean filter, bleed air). If flow is correct but the error persists, the flow switch is faulty.
When should you call an F-Gas engineer?
Estia R32 commissioning or winter without complete bleeding of the hydraulic circuit.
Affected models
- Estia R32
- Estia Series 5
Field context
Estia R32 commissioning or winter without complete bleeding of the hydraulic circuit.
Technical source data
The A01 Toshiba Estia (air/water) signals a water flow fault: clogged circuit, pipework >12 m with branches, or circulation pump. Procedure: bleed air, check integrated pump rotation, verify number of branches (minimum 5 recommended).
Sources: toshiba-estia-r32-service-manual.pdf (p. 121)
Questions fréquentes
Does the A01 Estia restart automatically?
The system attempts an automatic restart, but if the flow fault persists (pump, air, blockage), the A01 returns.
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