TradeAssistIQHome

Daikin Altherma fault AH-00

Tank disinfection function not completed correctly

Heat pump

What it means

Triggered when the disinfection setpoint is NOT reached within 6 hours or NOT kept for the required time. Unit will NOT stop operating.

Likely causes

  1. Large quantity of hot water has been tapped during/before disinfection
  2. Backup heater is restricted during disinfection
  3. Backup heater NOT allowed
  4. Faulty booster heater settings

Where to start

  1. Check when the disinfection is scheduled. Schedule it when there is little chance that water will be tapped so that the disinfection can finish in time
  2. Check the backup heater settings [2-00] to [2-04] and [4-00]
  3. Check the domestic hot water tank and booster heater related settings

The full answer, free

  • How to put it right, step by step
  • The manual page for this fault (page 31), right under the answer
Ask about AH-00 freeCreate a free account

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