Heat pumps · Error codes · Immergas
EPImmergas · MAGIS M monobloc R32 (M4-M30 T) - sold in UK as Alpha Magis M
EP on an Immergas MAGIS M monobloc R32 - sold in UK as Alpha Magis M: Leakage fault on tank booster heater (TBH)
Short answer
On an Immergas heat pump, EP means: Leakage fault on tank booster heater (TBH). 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: Leakage fault on tank booster heater (TBH).
Likely causes:
- Device connected to the TBH outputs.
Is it safe?
Switch the heat pump off at its isolator and call an engineer.
| Does the heat pump stop? | Not stated |
|---|---|
| Engineer needed? | Yes |
The manual does not say whether the heat pump stops.
Manual reset: Manual 13.4: reset the safety device by switching the unit off and back on; if this fails contact your local dealer.
What you can check
- Check the consumer-unit breaker/isolator for the heat pump is on.
- Note the code on the control panel and contact the installer / Alpha-Immergas authorised service.
- The manual says to reset the safety device by switching the unit off and back on; if the reset fails, contact the dealer - do not keep resetting.
What the engineer will check
- Device connected to the TBH outputs.
Who to ask for: heat pump engineer.
Certification: Electrical competence.
What you might notice
Sources
- MAGIS M4-30 Block heat pumps - Use and Installation - Instructions and warnings (IE edition), *1.046978ENG* ↗ · 1.046978ENG · page 126 · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026