Code U2: Malfunction of power supply or instantaneous power failure
Issue Description & Safety Warning
The Daikin SM-TS3 HVAC Self-Diagnosis has triggered a critical Malfunction of power supply or instantaneous power failure alarm. Immediate attention from a qualified operator or maintenance technician is required to prevent secondary damage to the equipment or spoiled parts during the manufacturing cycle. Always ensure standard safety and LOTO procedures are followed before accessing electrical cabinets.
Official Troubleshooting Steps
Unit area: System Product scope: RA, SkyAir, VRV, Package, Heat reclaim ventilator, Chiller, Fan Coil Chart object marker: kkkkkk Supposed causes: - Abnormal power supply voltage - Instantaneous power failure - Defective main circuit wiring
Source: Daikin SM-TS3 Simple Self-Diagnosis by Malfunction Code chart
Last reviewed: 2026-07-01 · Verified against the manufacturer’s official documentation.
About Daikin SM-TS3 HVAC Self-Diagnosis Alarms
Daikin controllers include extensive self-diagnostics that flag or halt the machine when a fault is detected. Error code U2 on the SM-TS3 HVAC Self-Diagnosis identifies one specific fault condition — its documented cause and the official corrective steps are listed above, sourced from Daikin's service documentation. Always confirm against the manual for your exact machine configuration and follow LOTO procedures before servicing.
Complete Alarm List: 139 Daikin SM-TS3 HVAC Self-Diagnosis codes.
Have a better solution?
Help the industrial community by sharing your repair experience for code U2.
Need a searchable reference for more Daikin SM-TS3 HVAC Self-Diagnosis manuals?
We structure equipment manuals into searchable code, title, cause, solution, safety note, and source-reference data. Send a PDF and example searched codes when you need public pages, private search, or structured exports.
Space reserved for Google AdSense / Industrial Affiliate Links
Monetization target for 2026