Daikin Altherma fault F6-00

What it means

Outdoor heat exchanger thermistor measures a too high temperature.

Likely causes

1. Closed stop valve in the refrigerant circuit
2. Refrigerant overcharge or shortage
3. Faulty refrigerant pressure sensor
4. Poor water flow through high pressure side plate heat exchanger
5. Incorrect refrigerant charge
6. High pressure switch confirmed faulty during checking procedure

Where to start

1. Check that all stop valves of the refrigerant circuit are open (see 4.2 Refrigerant circuit)
2. Check if the refrigerant circuit is correctly charged (see 4.2 Refrigerant circuit)
3. Check refrigerant pressure sensor