796 on an alpha innotec heat pump: Safety switch off: Safety input triggered; manual reset required. Case 1 inverter malfunction; case 2 high-pressure pressostats triggered; case 3 (LWDV/Hybrox only) voltage fluctuations beyond standard
Short answer
On an alpha innotec heat pump, 796 means: Safety switch off: Safety input triggered; manual reset required. Case 1 inverter malfunction; case 2 high-pressure pressostats triggered; case 3 (LWDV/Hybrox only) voltage fluctuations beyond standard. The heat pump stops until the fault clears or is reset. An engineer is needed to fix the cause.
Reviewed 23 September 2026 · 1 source
What it means
The manual says: Safety switch off: Safety input triggered; manual reset required. Case 1 inverter malfunction; case 2 high-pressure pressostats triggered; case 3 (LWDV/Hybrox only) voltage fluctuations beyond standard.
When it shows: Safety input triggered; manual reset required. Case 1 inverter malfunction; case 2 high-pressure pressostats triggered; case 3 (LWDV/Hybrox only) voltage fluctuations beyond standard.
Likely causes:
- Inverter malfunction.
- High-pressure pressostat triggered.
- LWDV/Hybrox: supply voltage fluctuations.
Is it safe?
Switch the heat pump off at its isolator and call an engineer.
| Does the heat pump stop? | Yes |
|---|---|
| Severity | Safety lockout |
| Engineer needed? | Yes |
The heat pump stops until the fault clears or is reset.
Resetting itself: no.
Manual reset: manual reset by installer/authorised service required.
What you can check
- Note the error number and text shown on the Luxtronik display.
- Acknowledge the message by pressing the rotary pushbutton for about 7 seconds (as the Luxtronik manual permits); if the same error reappears, contact your installer or ait customer service with the error number.
- Check the heat pump breakers/isolator at the consumer unit are on (do not open any casing).
What the engineer will check
- Case 1: check inverter.
- Case 2: check heating water throughflow, overflow, flow temperature sensor and high-pressure sensor.
- Case 3: unit must be turned off and re-secured manually.
Who to ask for: heat pump / heating engineer.
What you might notice
Sources
- Operating manual Luxtronik heating and heat pump control Part 2 (UK) 83055400lUK - 2.1 ↗ · 83055400lUK 2.1 · page 55 · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026