Heat pumps · Error codes · Alpha Heating Innovation
1123Alpha Heating Innovation · Alpha E-Tec Hybrid (E-Tec EHP 4 kW + E-Tec 33 HB boiler)
1123 on an Alpha Heating Innovation Alpha E-Tec Hybrid: Power supply voltage anomaly: Power supply voltage out of range
Short answer
On an Alpha Heating Innovation heat pump, 1123 means: Power supply voltage anomaly: Power supply voltage out of 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: Power supply voltage out of range.
Part involved: E-Tec EHP outdoor unit.
Likely causes:
- Check cable condition and connections; water ingress/short circuit.
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.
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 40 · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026