Why Morning Is the Hardest Time
A heat pump must work against the coldest outdoor temperatures of the day and heat a house that has cooled overnight. This combination means morning is when heat pumps are under most stress.
Common Morning Problems
- System in defrost mode at startup (normal in cold weather)
- House too cold because overnight setback was too large
- System set to come on too late — heat pump needs more lead time than a boiler
- Error code due to overnight low-temperature protection
Solutions
- Reduce overnight setback to 1–2°C rather than switching off
- Set the heat pump to start 30–60 minutes earlier than you want warmth
- If error codes appear overnight, note them and call an engineer
Sources: Microgeneration Certification Scheme and registered electrician.
