L8Daikin · VRV IV RXTQ-TA / RXTQ-TB · Heat Pump

Daikin VRV IV RXTQ-TA / RXTQ-TB error code L8

Compressor overcurrent

Needs attention soon

Also written as overcurrent, high current, L8

Which models this applies to. Outdoor unit

Quick answer

On Daikin VRV IV RXTQ-TA / RXTQ-TB, L8 is a fault. It means compressor overcurrent. A first thing to check: A refrigerant charge that is too low, which makes the compressor run without enough refrigerant to cool its windings.

Applies to: Daikin VRV IV RXTQ-TA / RXTQ-TB; Daikin VRV IV RXTQ heat pump codes · Heat Pump
Type of code: Fault; Urgency: Needs attention soon
First safe check: Check the outdoor fan is running and the coil is clean, because a condenser problem raises compressor current and is easy to check.

Checked 2026-09-26

What L8 means on this model

The compressor has drawn more current than the drive accepts over a period, and the outdoor unit has stopped. Sustained overcurrent means the compressor is working hard enough to be damaging itself, and low charge, a failing compressor and a condenser problem all present this way.

Symptoms you will notice

Outdoor unit shows L8 and the system stops
The system runs for a while then stops on high current
The system runs but is slow to reach setpoint
The compressor is warm to the touch at the terminal box

Common causes

The code tells you what the control detected, not which part failed. These are the causes we see most often, roughly in order of likelihood:

A refrigerant charge that is too low, which makes the compressor run without enough refrigerant to cool its windings
A failing or worn compressor
A condenser that is not rejecting heat, raising head pressure and compressor current
A non-condensing condition such as a dirty coil or a fan that has stopped
A supply voltage problem
An inverter or drive fault

What you can safely check

These are homeowner-level checks. None of them need you to open a live electrical compartment or work on gas.

Check the outdoor fan is running and the coil is clean, because a condenser problem raises compressor current and is easy to check.
Note whether the system is slow to cool as well as drawing high current, since that points at low charge rather than a compressor that has mechanically failed.
Check the supply voltage at the outdoor unit.

Do not do these

×Do not keep restarting on L8. Sustained overcurrent is the drive telling you the compressor is being destroyed.
×Do not add refrigerant without measuring the actual charge. On a system that genuinely has a failed compressor, added refrigerant does nothing and the compressor still fails.
×Do not work on the outdoor unit with the power switch on.

When to call a technician

Book a technician, do not keep resetting it

This fault will not clear on its own. Every power cycle gives the control one more failed attempt, and repeated attempts are what turn a cheap part replacement into a seized or contaminated system.

The refrigerant circuit is sealed and legally requires licensed handling. Opening it without certification releases refrigerant and can put the whole system in violation of regulation, so a low-pressure or high-pressure fault on this equipment is a call-out, not a weekend job.
If the appliance has stopped mid-cycle, is making a noise you have not heard before, or smells burnt, stop reading here and call. Those are symptoms of something the fault code does not describe well enough.

A licensed technician job. Checking that the outdoor fan runs and the coil is clean is a reasonable homeowner step.

What it costs to fix

Parts

Compressor $1,400 to $3,000 plus coil and filter drier. Condenser fan motor $300 to $700.

Labor

Four to eight hours including recovery, replacement and recharge.

DIY or technician