Article reference KA-02368
If there is a power cut, the Quantum will be unable to take an off-peak charge or run the fan until power has been restored.
Once power is restored, the Quantum should not need any input from yourself as the heater has a backup battery remembering the date & time and the settings are held.
That said, your Quantum may take a couple of days to settle back down to what feels like normal charging. This is because the Quantum learns how much charge is needed each night based on previous days performance, and this is re-learned after a power cut.
If there has been a power cut for several days and the house has gone cold, it may take a few days to heat up the fabric of the building in very cold weather conditions.
If after a power cut, your Quantum says "Heater Disabled", this means the backup battery requires replacement. We have two guides on how to change the battery:
If you have a Series A-G Quantum: Quantum Series A-G showing Heater disabled. What does this mean?
If you have a Series G5/G6/G7/G8/G9/G10/G11/Y/Z Quantum:
How do I change the battery on my Quantum heater? (Heater disabled, or clock time / date not remembered)
To help identify what series you have:
How do I identify what series my Quantum heater is?
Applicable to models: QM050 QM070 QM100 QM125 QM150 QM050RF QM070RF QM100RF QM125RF QM150RF