UGREEN NAS Temperature: What Is Too Hot and How to Fix It
UGOS Pro uses 80°C for the CPU, 55°C for HDDs, and 70°C for SSDs as cooling-protection thresholds. When a component reaches its threshold, the system displays a notification and switches the fan to Full Speed.
A brief temperature increase during indexing, transcoding, backup, or RAID activity does not necessarily mean the NAS is overheating. A temperature that remains elevated after the workload stops—or stays high while the NAS is idle—requires further investigation.
Check CPU, HDD, and SSD Temperatures
To check CPU temperature:
- Open Task Manager from the UGOS Pro desktop.
- Go to Running Status.
- Record the CPU temperature and current CPU usage.
To check HDD and SSD temperatures:
- Open Storage.
- Select Hard Drive.
- Open the HDD/SSD tab.
- Review the real-time temperature of each installed drive.
UGOS Pro uses the following protection thresholds:
| Component | UGOS Pro threshold | System response |
|---|---|---|
| CPU | 80°C | Notification and Full Speed fan mode |
| HDD | 55°C | Notification and Full Speed fan mode |
| SSD | 70°C | Notification and Full Speed fan mode |
Identify the Temperature Pattern
Record the temperatures under normal use, during the affected workload, and again after that workload ends.
| Temperature pattern | Likely scope | First action |
|---|---|---|
| CPU rises during transcoding, indexing, or a container workload | Compute load | Identify the process and test Full Speed fan mode |
| Every HDD and SSD rises together | Room temperature or chassis airflow | Check the intake, exhaust, placement, and fan |
| One drive remains hotter than the others | Drive model, installation, local airflow, or drive health | Compare the exact models and run a Status test |
| Temperatures remain high while the NAS is idle | Cooling problem or hidden background activity | Check Task Manager, fan response, and active services |
| Temperature rises during RAID repair or Data Organizing | Storage workload | Stop unrelated tasks and continue monitoring the repair |
A short spike that falls after the workload ends is different from a sustained temperature. If the CPU, HDD, or SSD remains close to its threshold while the NAS is idle, move to the cooling-system test.
Test the UGOS Pro Cooling Fan
Open:
Control Panel > Hardware & Power > General > Cooling fan > Settings
UGOS Pro provides three preset fan modes:
| Fan mode | How it behaves | When to use it |
|---|---|---|
| Auto | Adjusts fan speed according to device temperature | Normal daily use |
| Quiet | Reduces fan speed and cooling performance | Quiet rooms when temperatures remain controlled |
| Full Speed | Runs the fan at maximum speed | High temperature, heavy load, or cooling diagnosis |
Auto is the best starting point for normal operation. Quiet mode can allow components to run warmer, so switch back to Auto if the NAS temperature rises.
Use Full Speed to test whether the installed cooling system can reduce the temperature:
- Record the current CPU, HDD, and SSD readings.
- Switch the cooling fan to Full Speed.
- Confirm that airflow and fan noise increase.
- Keep the current workload stable and watch the temperature trend.
- Return to Auto after the test if temperatures have stabilized.
If airflow increases and temperatures fall, the cooling hardware is working. The remaining cause is likely the fan profile, room temperature, placement, or workload.
If Full Speed produces little or no airflow, or the fan does not respond, do not replace it yourself. Record the model, firmware version, temperature readings, fan behavior, and active workload before contacting UGREEN Support.
If Full Speed solves the heat problem but is too loud for daily use, our guide to reducing UGREEN NAS noise safely explains how placement and distance can reduce perceived noise without restricting airflow.
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Fix Airflow and Room-Temperature Problems
A NAS fan moves surrounding air through the chassis. It cannot cool the components below the temperature of the air entering the enclosure.
The right solution therefore depends on where the NAS is installed:
| Placement | Main risk | Better setup |
|---|---|---|
| Open shelf in a living area | Objects blocking the intake or exhaust | Keep vents unobstructed and point the exhaust away from where people sit |
| Media cabinet | Warm exhaust recirculating inside the cabinet | Use a ventilated cabinet with a clear intake and exhaust path |
| Closed closet | Heat accumulating around the NAS | Relocate the NAS or add effective room-level ventilation |
| Garage or attic | High seasonal temperature and humidity | Move the NAS into a climate-controlled space |
| Beside a router, amplifier, mini PC, or UPS exhaust | Hot air entering the NAS | Separate the devices so their exhaust paths do not feed each other |
Do not seal a NAS inside a cabinet to hide fan or drive noise. If Quiet mode raises the temperature, move the NAS farther away or improve the room layout instead of restricting the airflow.
Check the entire intake and exhaust path:
- Nothing should cover the ventilation openings.
- Cables should not sit against the exhaust.
- Dust filters should not be clogged.
- Other equipment should not blow warm air toward the NAS.
- The expelled air needs a path out of the shelf or cabinet.
If every component becomes warmer at the same time, the enclosure is unlikely to contain several simultaneous hardware faults. Ambient heat or restricted chassis airflow is the more useful starting point.
What to Check When One HDD or SSD Runs Hotter
Different HDD models can have different RPM, power consumption, platter design, and cooling requirements. Start by comparing:
- The exact model number of each drive
- Whether the drives are HDDs, SATA SSDs, or M.2 SSDs
- Their current workload
- Their temperature history
- Their power-on hours and health status
- Any warning shown by UGOS Pro
If identical drives in the same storage pool normally run close together and one begins staying hotter, open:
Storage > Hard Drive > HDD/SSD > affected drive > Details
Review its temperature and SMART information. Then run a Status test after the temperature has returned below the UGOS Pro threshold.
Temperature alone does not diagnose a failed drive. Reallocated sectors, pending sectors, spin-retry changes, unusual noises, or a UGOS Pro health warning make the situation more serious. Protect the data and follow the process for replacing a failing UGREEN NAS drive when temperature and health warnings appear together.
Do not move an active RAID member into another bay as a temperature test. Drive order and storage-pool state matter, and casual relocation creates unnecessary risk.
Check M.2 SSD Installation
An M.2 SSD can run considerably warmer than an HDD, especially under sustained writes, cache activity, or application workloads. UGOS Pro uses 70°C as the SSD cooling-protection threshold.
If an M.2 SSD runs hot:
- Shut down and unplug the NAS.
- Open only the user-serviceable M.2 cover.
- Confirm that the supplied thermal pad is installed.
- Verify that its protective film was removed.
- Check that the pad contacts the SSD correctly when the cover is installed.
- Confirm that the SSD and any installed heatsink do not prevent the cover from closing properly.
Use a compatible SSD and the cooling parts designed for the NAS. An oversized aftermarket heatsink can interfere with the cover or direct heat into the wrong part of the enclosure.
Temperature Spikes During Heavy Workloads
NAS temperatures often rise during work that keeps the CPU or drives active for an extended period.
Common examples include:
- RAID synchronization or storage-pool repair
- Data Organizing on RAID 5 or RAID 6
- Photo indexing and AI categorization
- Thumbnail generation and media analysis
- Plex or Jellyfin transcoding
- Docker containers
- Virtual machines
- Large backup or synchronization tasks
Open Task Manager when the temperature rises and identify which process or application is using the CPU. Check Storage for active repair, synchronization, or Data Organizing work.
If several demanding tasks overlap, stagger the nonessential work. For example, avoid running a large backup, media indexing, and video transcoding during Data Organizing.
A storage-pool repair should not be canceled casually. Reduce unrelated applications, switch the fan to Full Speed, and continue monitoring the component temperatures. If a sensor remains at its protection threshold after unrelated workloads stop, move to the shutdown and support checks below.
If the temperature is controlled but the NAS remains slow, continue with the separate UGREEN NAS performance diagnostic sequence. High utilization and inadequate cooling are different problems even when they occur at the same time.
Clean Dust Without Damaging the NAS
Dust can block an intake, coat fan blades, and reduce heat transfer. The amount of cleaning required depends on the room, pets, carpet, smoke, and local dust—not a universal monthly or quarterly schedule.
Before cleaning:
- Stop active file transfers and storage tasks.
- Shut down the NAS through UGOS Pro.
- Disconnect the power cable.
- Remove only user-serviceable trays, filters, and covers.
- Clean accessible intake and exhaust areas.
- Use short bursts of compressed air while keeping the can upright.
- Prevent the fan blades from spinning freely under compressed air.
- Keep liquids away from the chassis and drives.
Do not blow dust deeper into the NAS or disassemble cooling hardware beyond the supported user-serviceable areas. The complete UGREEN NAS maintenance checklist covers cleaning alongside drive tests, storage maintenance, updates, and backup verification.
After cleaning, reinstall every tray and cover, reconnect the NAS, and compare temperatures under the same workload used before cleaning.
When Should You Shut Down the NAS?
Reaching a UGOS Pro temperature threshold causes a notification and Full Speed fan response. Stop unrelated workloads and monitor whether the temperature falls.
Shut down the NAS when:
- A component stays at or above its threshold after unrelated workloads stop.
- Full Speed mode produces no noticeable airflow.
- The fan stops, grinds, or repeatedly fails to start.
- The NAS produces a burning smell.
- The system shuts down unexpectedly.
- An HDD is hot and also reports a health warning.
- An SSD reaches its threshold despite correct thermal-pad installation.
- Temperature alerts return immediately after restarting the NAS.
If you smell burning or see smoke, disconnect power when it is safe to do so and do not restart the NAS.
Before contacting UGREEN Support, record:
- NAS model
- UGOS Pro version
- CPU, HDD, and SSD temperatures
- Fan mode
- Ambient room temperature
- Current applications and workloads
- Drive models and health status
- Time and wording of each temperature notification
- Whether Full Speed mode increased airflow
A brief temperature spike does not prove that data has been damaged. Persistent overheating increases hardware and shutdown risk, so verify that important files remain accessible and that an independent backup can be restored. RAID availability does not replace that backup.
Frequently Asked Questions
What temperature is too hot for a UGREEN NAS?
UGOS Pro uses 80°C for the CPU, 55°C for HDDs, and 70°C for SSDs as cooling-protection thresholds. When a component reaches its threshold, the system displays a notification and switches the fan to Full Speed.
Where can I check UGREEN NAS CPU and drive temperatures?
Open Task Manager and go to Running Status to view CPU temperature. For HDD and SSD temperatures, open Storage, select Hard Drive, and use the HDD/SSD tab.
Why is one NAS drive hotter than the others?
Different drive models can have different RPM, power use, mechanical designs, and cooling requirements. Compare the exact models, current workload, temperature history, and health data. If one identical drive becomes persistently hotter than its peers, run a Status test and review its SMART information.
Does Quiet fan mode increase NAS temperature?
Quiet mode lowers fan speed, so cooling performance is reduced and component temperatures can rise. Auto is recommended for normal daily use. Switch to Full Speed when diagnosing elevated temperatures or operating under sustained heavy load.
Can I use these steps with TrueNAS or Unraid?
The UGOS Pro menu paths, notifications, temperature thresholds, and automatic fan behavior described here apply to UGOS Pro. A NAS running TrueNAS, Unraid, or another replacement operating system requires the monitoring and fan-control procedures provided for that system.
