H16

Outdoor Current Transformer (CT) Abnormality

Home Appliance Error Codes Panasonic Split AC

Can you still use it? No, unplug it

Who can fix it? Needs an authorized technician

Typical repair time 1 hour – 4 hours

Typical cost SAR 150 to 2,500

What it means

This code appears on Panasonic inverter split air conditioners and is read with the CHECK button. It means the outdoor board measures, through its current transformer (CT), far less current than expected while the compressor is running, so either the measurement has failed or the compressor is not carrying its normal load, as happens when refrigerant is low. The unit stops the compressor for protection, and the same number can mean something else on other brands.

Models covered: Panasonic residential inverter split air conditioners (wall mounted); the code is read with the CHECK button on the remote control.

Symptoms4

Cooling stops and a lamp blinks on the indoor unit.
The outdoor unit runs briefly and then stops.
Cooling may have been weak for days before the code if refrigerant is low.
The code returns after every restart.

Possible causes5

Low refrigerant from a leak, which lowers the compressor load and current.
A fault in the current transformer (CT) circuit on the outdoor board.
Another fault on the outdoor inverter board.
Loose compressor connections or board wiring.
Service valves left partly closed after installation or service.

How to diagnose5

Switch the unit off at the breaker for a few minutes and restart it once only, then see whether the code returns.
Tell the technician when refrigerant was last added and whether cooling faded gradually.
The technician checks refrigerant pressure and pipe temperatures against the manufacturer specification and looks for a leak.
The technician confirms the service valves are fully open.
If the refrigerant circuit is good, the technician checks the current sensing on the outdoor board using the service manual.

How to fix5

Fully open the service valves if they were found partly closed.
Repair the leak and recharge refrigerant by weight; this is work for a licensed technician.
Tighten compressor and board connections and repair any corroded connector.
Replace the outdoor board if the current sensing circuit is faulty.
Run the unit, check its performance and confirm the code does not return in the fault history.

Repair cost

0–200

200–600

600–1,500

1,500+

In Saudi riyals; the highlighted part is the expected range for this fault.

The cost is low for a closed valve or loose connection, moderate for leak repair and recharge, and highest when the outdoor inverter board must be replaced.

Prices are rough estimates including the part and the technician’s fee, and vary with brand, model and part source.
Prices last updated: September 2026

Frequently asked questions

How can low refrigerant cause an electrical code?

With less refrigerant, the compressor works less and draws less current, so the board thinks the current reading is faulty. That is why refrigerant is checked before the board is replaced.

Should I keep restarting the unit?

No, try once only. Repeated starts with low refrigerant put stress on the compressor.

Was this explanation helpful?

Tap the stars to rate; you can change it later.

This guide is for information only and does not replace an inspection by a qualified technician. If the fault involves brakes, steering, engine temperature, electrics or refrigerant, do not attempt the repair yourself.

Report a mistake

Spotted something inaccurate? Tell us and we will review and correct it.