Daikin VRV IV RXTQ-TA / RXTQ-TB error code UF
System not set yet
Which models this applies to. System
Quick answer
On Daikin VRV IV RXTQ-TA / RXTQ-TB, UF is a fault. It means system not set yet. A first thing to check: The system has not been commissioned.
- Applies to
- Daikin VRV IV RXTQ-TA / RXTQ-TB
- Daikin VRV IV RXTQ heat pump codes · Heat Pump
- Type of code
- Fault
- Urgency: Book a technician
- First safe check
- Check with the installer whether the system has been commissioned, since this code is about system setup rather than a failed part.
What UF means on this model
The system has not been set up, so it does not yet know what indoor units are connected. This is a commissioning code shown by a factory fresh system before it has been addressed and configured, and it means not set rather than broken.
Symptoms you will notice
- System shows UF and will not start
- The system is newly installed
- The system has been powered on for the first time
- The system was stored or reset and has lost its configuration
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:
- The system has not been commissioned
- The system configuration has been cleared or reset
- A replacement outdoor unit has been fitted without the system being set up
- The system was stored before installation
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 with the installer whether the system has been commissioned, since this code is about system setup rather than a failed part.
- Check whether the outdoor unit has recently been replaced, because a replacement outdoor unit needs the system to be set up again.
Do not do these
- ×Do not try to bypass this from the room controller. System setup is what tells the outdoor unit what it is connected to.
- ×Do not assume anything has failed. UF means not set, not broken.
When to call a technician
Worth scheduling, and worth your own checks first
You can usually keep living with this for a short while, but it will not fix itself. Do the safe checks below first, because a tripped switch or a blocked airflow is a five-minute fix that would otherwise cost you a service call.
- 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 commissioning technician job. System setup needs the manufacturer tools.
What it costs to fix
Parts
None expected.
Labor
Two to four hours for the commissioning technician to set the system up.
DIY or technician
A commissioning technician job. System setup needs the manufacturer tools.
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
- Models in scope
- Daikin VRV IV RXTQ-TA / RXTQ-TB
- 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.