Temp Fault on a Fox ESS H1 G2 single-phase hybrid inverter: The inverter temperature is high
Short answer
On a Fox ESS inverter, Temp Fault means: The inverter temperature is high. The inverter stops until the fault clears or is reset.
Reviewed 24 September 2026 · 1 source
What it means
The manual says: The inverter temperature is high.
Part involved: inverter thermal protection.
When it shows: Internal temperature above limit.
Likely causes:
- High ambient temperature, poor ventilation, blocked cooling fins.
Is it safe?
| Does the inverter stop? | Yes |
|---|---|
| Severity | Fault — clears by itself when the condition goes |
The inverter stops until the fault clears or is reset.
Resetting itself: yes.
Manual reset: Wait for a while to check if back to normal.
What you can check
- Read the full code and message on the inverter screen or in the FoxCloud app and note the date/time for your installer.
- Check the inverter's AC isolator next to the inverter and the solar/battery breaker in the consumer unit are ON (do not reset a breaker that trips again - call your installer).
- Check nothing is stacked against or covering the inverter and the space around it is not unusually hot (e.g. a closed loft in summer) - do not open the unit.
What the engineer will check
- Check clearances and ventilation per manual; clean cooling fins; check fan (where fitted) and derating logs.
Who to ask for: Qualified electrician / MCS PV installer.
Certification: Work on DC strings and inverter enclosures: competent PV installer (MCS-certified installer for warranty/SEG continuity); electrical work notifiable under Part P (England & Wales) or equivalent.
What you might notice
Sources
- H1(G2)/AC1(G2) Series User Manual ↗ · V1.0.8 · page 48 · Reviewed 24 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 24 September 2026