Heat pumps · Error codes · Alpha Heating Innovation
1020Alpha Heating Innovation · Alpha E-Tec Hybrid (E-Tec EHP 4 kW + E-Tec 33 HB boiler)
1020 on an Alpha Heating Innovation Alpha E-Tec Hybrid: Power supply voltage anomaly: The supply voltage to the outdoor unit is out of the normal range
Short answer
On an Alpha Heating Innovation heat pump, 1020 means: Power supply voltage anomaly: The supply voltage to the outdoor unit is out of the normal range. The manual does not say whether the heat pump stops. An engineer is needed to fix the cause.
Reviewed 23 September 2026 · 1 source
What it means
The manual says: Power supply voltage anomaly: The supply voltage to the outdoor unit is out of the normal range.
Part involved: E-Tec EHP outdoor unit.
Likely causes:
- Check cable condition and connections; water ingress/short circuit; main power supply, consumer unit and breaker.
Is it safe?
| Does the heat pump stop? | Not stated |
|---|---|
| Engineer needed? | Yes |
The manual does not say whether the heat pump stops.
What you can check
- Note the code and any text shown on the display/controller.
- Check the heat pump isolator and consumer-unit breaker are on.
What the engineer will check
- Check cable condition and connections.
- water ingress/short circuit.
- main power supply, consumer unit and breaker.
Who to ask for: heat pump engineer.
Sources
- Alpha E-Tec Hybrid - Installation Instructions (package, 06-23) ↗ · E-Tec Hybrid package instructions 06-23 · page 39 · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026