Felicity Inverter Beeping? What the Beeps & Red Light Mean

Your Felicity inverter is beeping and a red light is on — and you want it to stop. Good news: the beeping is not random. The buzzer and the red LED are telling you exactly one of two things, and the number sitting on the LCD tells you what to do about it. Two questions solve this: is the beep continuous or intermittent, and is the red light solid or flashing?

What the beeps mean

On IVPS/IVPM models, Felicity uses one buzzer pattern for each alarm class:

• Continuous beep, red LED solid, power gone: a fault. The inverter has detected a problem serious enough to cut its own output and protect itself. The buzzer keeps going and the fault code sits steady on the LCD.
• Intermittent beeping, red LED flashing, appliances still running: a warning. The unit keeps working, but it wants you to act before the situation escalates. The code flashes on the LCD.

On the T-REX hybrid inverters the overload alarm has its own signature: the buzzer beeps twice every second when the connected load exceeds the continuous output rating, and if the load is not reduced, protection cuts the output.

Not every beep is an alarm, either. On IVPS models the buzzer sounds for 2.5 seconds when you switch the inverter on or off, gives a 0.1-second chirp when you press a button, and a 3-second tone when you hold ENTER. A single beep at power-on is normal behavior, not an error.

Read the code next to the light

The beep tells you how serious; the number on the LCD tells you what. That number is the actual answer, so read it before switching anything off. If your screen shows F15, search for 15 — the directory merges both notations onto one page and shows the meaning for your exact model.

Then type it into the Felicity error-code lookup — 1,356 codes across 46 devices, each with the official cause and the recommended fix for your exact model. That matters, because the same number can mean different things on different Felicity families.

The codes that beep most often

Overload — 01 warning, 13 fault, 09 on T-REX

The single most common reason a Felicity inverter beeps. On IVPS/IVPM models, intermittent beeping with warning 01 means the connected load is above the rated output power — reduce the load, because how long the unit tolerates it depends on the load percentage. If you don't, it escalates to fault 13: continuous beep, output cut. Switch off, drop the load below the rating, switch back on — and if the overload happened with the AC input connected, the fault clears itself after about 30 seconds. On the T-REX-3K to 6K hybrids the overload code is 09 (W09 on the 10 kW three-phase models): that is the twice-per-second beep described above.

Low battery — 04

On IVPS/IVPM models, intermittent beeping with code 04 means the battery has discharged below the low-voltage warning level. The battery needs charging — and it is worth checking what drained it, especially if this happens on a sunny day.

Over temperature — 18

On IVPS/IVPM models, continuous beep, output cut: the inverter's internal temperature is too high. Switch it off and let it cool down; once the temperature is back to normal it can be used again. Clear the vents and keep the unit out of direct sun so code 18 doesn't come back. On other Felicity families the same number can mean something else entirely — the code page shows the meaning per model.

Output short — 15

On IVPS/IVPM models, continuous beep, output cut, and the most urgent of the four: a short circuit detected on the AC output — in the wiring or in a connected appliance. If the AC input is on, cut it off first, then switch the inverter off, disconnect all AC output wiring, and switch it back on. If the screen still shows 15 with nothing connected, the fault is internal — stop and get service. If it starts cleanly, check the output wiring and loads and make sure none of them are short-circuited before reconnecting.

When the beeping means call someone

A fault that comes straight back after a restart — especially with all loads disconnected — is the inverter telling you the cause is still there. Don't keep power-cycling it. Note two things: the code on the screen and your model name (on the label on the side of the unit). With those two, a technician can usually tell you over chat whether it is a wiring issue, a battery issue, or an internal fault that needs a repair visit.

📞 Beeping won't stop after these steps? Send the code and model to a technician on WhatsApp +971 54 289 9793 — free lifetime support is included with every unit we supply. Prefer to talk? Call us or use the contact page.