Daikin VRV IV RXTQ-TA / RXTQ-TB error code L5
Compressor instantaneous overcurrent
Which models this applies to. Outdoor unit
What is specific to the VRV IV RXTQ-TA / RXTQ-TB platform
The RXTQ outdoor unit serves VRV indoor units over a shared communication bus, and the factory splits the code list by which unit reports it. A and C codes come from indoor units, E, F, H, J, L and P from the outdoor unit, and U and M are system or centralized controller faults. This is a commercial and light commercial multi split platform, not a residential one indoor mini split unit.
Your control board prints the code as text, for example F01 or EE3, so you read it off the display rather than counting blinks. The printed number is the fault itself, not a position in a table.
Quick answer
On Daikin VRV IV RXTQ-TA / RXTQ-TB, L5 is a fault. It means compressor instantaneous overcurrent. A first thing to check: A supply voltage that is too low, which makes the compressor draw excessive current trying to start.
- 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
- Measure the supply voltage at the outdoor unit under load, since a marginal supply often looks acceptable at no load.
What L5 means on this model
The compressor drew more current than the drive accepts in a single moment. This is the drive reacting fast to a spike, which distinguishes it from the sustained overcurrent code. A marginal supply voltage and a hard to start compressor are the usual causes.
Symptoms you will notice
- Outdoor unit shows L5 and the system stops
- The system stops on startup
- The system will not restart
- The supply voltage is marginal at the outdoor unit
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 supply voltage that is too low, which makes the compressor draw excessive current trying to start
- A supply voltage that is too high
- A hard to start or failing compressor
- An inverter or drive fault
- A loose or corroded supply connection at the outdoor unit
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.
- Measure the supply voltage at the outdoor unit under load, since a marginal supply often looks acceptable at no load.
- Note whether the fault is immediate on every start or intermittent, since intermittent points to a supply or connection problem and consistent points to the compressor or drive.
- Check the supply connections at the outdoor unit for tightness and corrosion.
Do not do these
- ×Do not keep restarting on L5. Repeated overcurrent trips will damage the drive section and the compressor windings.
- ×Do not install a larger supply fuse to stop the trip from happening. That removes the protection that is doing its job.
- ×Do not work on the supply connections 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 technician job. Measuring supply voltage under load is not a homeowner task.
What it costs to fix
Parts
Compressor $1,400 to $3,000. Inverter PCB $500 to $1,200. Supply terminals $20 to $60.
Labor
Three to six hours depending on whether the cause is electrical or mechanical.
DIY or technician
A technician job. Measuring supply voltage under load is not a homeowner task.
Typical US part and labor ranges, 2026. They vary by region, model and contractor, so treat them as a planning figure, not a quote.
Scope of this code
- Code table
- Daikin VRV IV RXTQ heat pump codes
- How this model reports the code
- Printed on the control display
- Models in scope
- Daikin VRV IV RXTQ-TA / RXTQ-TB
- How this platform differs
- The RXTQ outdoor unit serves VRV indoor units over a shared communication bus, and the factory splits the code list by which unit reports it. A and C codes come from indoor units, E, F, H, J, L and P from the outdoor unit, and U and M are system or centralized controller faults. This is a commercial and light commercial multi split platform, not a residential one indoor mini split unit.
- Checked
- Confirm on your own unit
- Find the model number on the data plate, then check this code in the service manual for that model. Manufacturers revise code tables between model years, and a revised board can renumber a fault.