Samsung DVM Systems — What You Need to Know
Samsung VRF systems are branded as the DVM series — DVM S, DVM S2, DVM Eco, DVM Plus IV, DVM Chiller. They’ve grown rapidly in the Australian commercial market, with competitive pricing and strong multi-tenant features winning projects that used to default to Daikin or Mitsubishi.
- Samsung uses a proprietary 2-wire communication bus (F1/F4 or F3/F4) between outdoor and indoor units
- Error codes display on the wired remote controller (MWR series), the outdoor unit PCB LED, or via Samsung DMS (Device Management System) cloud platform
- Codes use an alphanumeric format: E1xx for outdoor, E2xx for indoor, E4xx for communication, E5xx for optional equipment
- The prefix tells you immediately where to look — outdoor, indoor, or communication bus
Samsung error codes follow a logical structure: E1xx = outdoor unit, E2xx = indoor unit, E4xx = communication, E5xx = optional equipment. Knowing the prefix tells you immediately where to look.
“Samsung error codes follow a logical structure: E1xx outdoor, E2xx indoor, E4xx communication. The prefix tells you where to look.”
Communication Faults (E4xx)
Communication faults on Samsung systems follow the same pattern as every other VRF brand — they start intermittent, nobody notices, and then one day they’re persistent. The F3/F4 bus is polarity-sensitive.
E401
Communication error between outdoor and indoor units
What it means
The outdoor unit has lost communication with one or more indoor units via the F3/F4 bus.
What to check first
Check the 2-wire communication cable (F3/F4). Verify polarity — Samsung IS polarity-sensitive. Measure communication voltage across F3/F4 terminals. Check for damaged wiring, water ingress, loose terminals at both ends.
Common cause
Reversed polarity on one indoor unit. Damaged comm cable during construction. Water ingress into junction box.
Nexus iQ advantage: Communication faults are intermittent before they become persistent. Nexus iQ logs every communication timeout with a timestamp — you see exactly which unit dropped and when.
↓ Back to searchE402
Communication error between outdoor units
What it means
In a multi-outdoor-unit system, inter-unit communication has failed.
What to check first
Check inter-unit communication cable. Verify master/sub addressing. Check for duplicate addresses.
↓ Back to searchE404
Communication error with wired remote controller
What it means
The wired controller has lost communication with the indoor unit.
What to check first
Check the 2-wire connection from controller to indoor unit PCB. Verify address setting. Power cycle the controller.
↓ Back to searchE405
Communication error with central controller
What it means
The central controller (AC EZ, DMS) has lost communication with the system.
What to check first
Check the communication bus from central controller to the network. Check RS485 wiring. Verify addressing.
↓ Back to searchE416
Address setting error / Duplicate address
What it means
Indoor unit address conflict or address not set.
What to check first
Verify all indoor unit addresses are unique. Re-address via DIP switches or controller setup.
↓ Back to searchE421
Communication error with optional equipment
What it means
Communication failure with optional device (ventilator, ERV, etc.).
What to check first
Check wiring to the optional device. Verify address setting.
↓ Back to searchOutdoor Unit Refrigerant & Pressure Faults (E1xx)
E101
High pressure fault
What it means
Discharge pressure has exceeded the high pressure switch setpoint.
What to check first
Check condenser coil for blockage (leaves, debris, recirculation). Verify condenser fan operation. Check refrigerant charge — overcharge causes high pressure. Check outdoor ambient temperature.
Common cause
Dirty condenser coil. Condenser fan failure. Refrigerant overcharge.
Nexus iQ advantage: Repeated high pressure trips stress the compressor. Each event reduces compressor life. Monitoring tracks frequency and duration.
↓ Back to searchE102
Anti-freeze protection
What it means
Indoor coil temperature dropped too low, freeze protection activated.
What to check first
Check indoor fan operation. Check air filter. Check evaporator coil for dirt. Verify refrigerant charge.
↓ Back to searchE103
Low pressure fault
What it means
Suction pressure has dropped below the minimum threshold.
What to check first
Check refrigerant charge. Look for restrictions — blocked filter drier, kinked pipe, closed service valve. Check EEV operation. Check for ice on evaporator.
Common cause
Slow refrigerant leak. Blocked filter drier.
↓ Back to searchE104
High discharge temperature
What it means
Compressor discharge temperature exceeded safe limit.
What to check first
Check refrigerant charge. Check condenser airflow. Verify EEV operation. Check for non-condensables.
Nexus iQ advantage: Discharge temperature trending is the most valuable diagnostic data point. A gradual rise over weeks signals trouble long before E104 triggers.
↓ Back to search“Discharge temperature trending is the most valuable diagnostic. Watch it, and you’ll predict 80% of compressor faults.”
E105
Low discharge temperature
What it means
Discharge temperature abnormally low — possible liquid slugging.
What to check first
Check superheat at compressor. Check EEV for stuck-open condition. Check crankcase heater.
↓ Back to searchE106
Suction temperature too high
What it means
Suction temperature is above normal, indicating low refrigerant flow.
What to check first
Check refrigerant charge. Check EEV operation. Check for restrictions.
↓ Back to searchE107
Outdoor heat exchanger sensor fault
What it means
The condenser coil temperature sensor is reading out of range.
What to check first
Measure thermistor resistance. Check connector. Replace if open circuit.
↓ Back to searchE109
Compressor shell temperature too high
What it means
Compressor body temperature exceeded the safe limit.
What to check first
Check refrigerant charge. Check condenser airflow. Check compressor cooling.
↓ Back to searchCompressor & Inverter Faults (E1xx continued)
These are the expensive ones. A compressor replacement on a Samsung DVM system runs $8,000–$16,000. An inverter IPM/IGBT module is $2,500–$3,000.
E121
Compressor overcurrent
What it means
The inverter has detected overcurrent on the compressor motor.
What to check first
Check compressor insulation resistance (megger test). Check for liquid slugging — verify superheat. Check incoming voltage — all three phases.
Nexus iQ advantage: Compressor replacement on a Samsung DVM: $8,000–$16,000. Catching overcurrent early prevents catastrophic failure.
↓ Back to searchE122
Inverter overcurrent (instantaneous)
What it means
Short-duration current spike detected on inverter output.
What to check first
Check compressor winding insulation. Check for short circuits. Check for moisture in electrical compartment.
↓ Back to searchE123
Inverter IPM / IGBT fault
What it means
The power module in the inverter has detected a fault.
What to check first
Check the IPM/IGBT module for damage or burn marks. Check heatsink temperature and fan. Check incoming voltage quality. Module replacement if persistent.
Nexus iQ advantage: IPM faults are preceded by weeks of elevated inverter temperature. A $200 cleaning prevents a $3,000 module replacement.
↓ Back to search“A $200 heatsink cleaning prevents a $3,000 inverter module replacement.”
E128
Inverter heatsink overtemperature
What it means
The inverter heatsink temperature exceeded the safe limit.
What to check first
Check heatsink for dust buildup. Verify heatsink fan operation. Check refrigerant charge — inverter is cooled by refrigerant on Samsung systems.
↓ Back to searchE130
Compressor startup failure
What it means
The compressor failed to start within the expected time.
What to check first
Check compressor wiring. Verify voltage at inverter output. Check for locked rotor. Try starting in different mode.
Common cause
Liquid refrigerant migration to crankcase. Failed crankcase heater.
↓ Back to searchE131
Compressor over-speed
What it means
Compressor frequency exceeded maximum RPM limit.
What to check first
Check refrigerant charge (undercharge causes high frequency). Check for restrictions.
↓ Back to searchE132
Phase reversal / Open phase
What it means
Incorrect phase sequence or a phase is missing.
What to check first
Check all three phases at outdoor unit terminals. Verify phase rotation. Check for single-phasing.
Common cause
Power outage recovery. Loose phase connection.
↓ Back to searchE134
DC link overvoltage
What it means
The DC bus voltage inside the inverter is too high.
What to check first
Check incoming voltage for spikes. Check for regenerative energy from compressor deceleration. Check inverter board.
↓ Back to searchE135
DC link undervoltage
What it means
The DC bus voltage is too low.
What to check first
Check incoming voltage under load. Check for voltage sag. Check capacitors on the inverter board.
↓ Back to searchStop chasing Samsung fault codes.
Nexus iQ monitors discharge temperature, compressor frequency, and communication health 24/7 — so you catch problems before they become fault codes.
See How It WorksIndoor Unit Faults (E2xx)
E201
Indoor room temperature sensor fault
What it means
Return air temperature sensor reading out of range or open circuit.
What to check first
Measure thermistor resistance (10kΩ at 25°C typical). Check connector on PCB. Check for physical damage.
Common cause
Sensor displaced during filter cleaning. Wire pinched during install.
↓ Back to searchE202
Indoor pipe (coil) sensor fault
What it means
Indoor coil temperature sensor has failed.
What to check first
Measure resistance. Check placement on evaporator coil. Replace if open circuit.
↓ Back to searchE203
Indoor discharge sensor fault
What it means
The indoor unit discharge air temperature sensor has failed.
What to check first
Measure resistance. Check placement. Replace if faulty.
↓ Back to searchE207
Indoor fan motor fault
What it means
Indoor fan motor has failed or feedback signal abnormal.
What to check first
Check motor resistance. Check for obstruction. Check bearings. Check connector.
Common cause
Dust buildup on fan wheel. Bearing failure.
↓ Back to searchE210
Indoor EEV fault
What it means
Electronic expansion valve on indoor unit not responding.
What to check first
Check EEV coil resistance. Verify EEV driver on PCB. Check wiring. Listen for EEV actuating.
↓ Back to searchE213
Drain pump fault / Float switch
What it means
Condensate drain overflow or float switch activated.
What to check first
Clear drain line. Check float switch. Clean drain pan. Verify drain pump.
Common cause
Blocked drain (algae, dirt). Kinked drain hose.
↓ Back to searchE218
Indoor PCB fault
What it means
Indoor control board internal error.
What to check first
Power cycle. Check voltage. PCB replacement if persistent.
↓ Back to searchOutdoor Unit Sensor & System Faults
E151
Outdoor air temperature sensor fault
What it means
Ambient temperature sensor failed or out of range.
What to check first
Measure thermistor resistance. Check connector. Replace if open circuit.
↓ Back to searchE152
Discharge temperature sensor fault
What it means
Compressor discharge pipe sensor failed.
What to check first
Measure resistance. Check placement on discharge pipe.
↓ Back to searchE153
Suction temperature sensor fault
What it means
Suction pipe temperature sensor out of range.
What to check first
Measure resistance. Check placement on suction pipe.
↓ Back to searchE154
Outdoor fan motor fault
What it means
Condenser fan motor has failed or is drawing excessive current.
What to check first
Check motor resistance. Check for obstructions. Check bearings. Check connector on PCB.
↓ Back to searchE156
Four-way valve fault
What it means
The reversing valve has not switched correctly.
What to check first
Check 4-way valve coil continuity. Listen for switching sound. Compare discharge and suction temperatures.
↓ Back to searchE160
Oil recovery fault
What it means
Oil not returning to compressor properly.
What to check first
Check oil level. Verify oil recovery piping. Check refrigerant charge.
↓ Back to searchE170
EEPROM fault (outdoor)
What it means
Memory chip read/write error on outdoor PCB.
What to check first
Full power cycle (disconnect 2 minutes). PCB replacement if persistent.
↓ Back to searchWhat Monitoring Catches
Samsung error codes tell you what’s broken. Monitoring tells you what’s about to break.
| WITHOUT MONITORING | WITH NEXUS iQ |
|---|---|
| Fault code → emergency callout | Trend → scheduled service |
| No history before fault | Full data: temps, pressures, Hz, runtime |
| Guessing which unit in a DVM system | Nexus pinpoints exact unit |
| $2,000–$5,000 emergency callout | $200 preventive service |
| Compressor fails → $8,000–$16,000 | Stress caught early |
The most expensive fault code is the one you could have prevented. Monitoring doesn’t stop failures — it stops surprises.
Quick Reference Table
Use this searchable table to quickly find any Samsung DVM fault code. Type a code (e.g., E401) or a keyword (e.g., pressure) to filter.
| Code | Category | Description | Severity |
|---|---|---|---|
| E101 | Refrigerant | High pressure fault | Critical |
| E102 | Refrigerant | Anti-freeze protection | Warning |
| E103 | Refrigerant | Low pressure fault | Critical |
| E104 | Refrigerant | High discharge temperature | Critical |
| E105 | Refrigerant | Low discharge temperature | Warning |
| E106 | Refrigerant | Suction temperature too high | Warning |
| E107 | Sensor | Outdoor heat exchanger sensor | Warning |
| E109 | Compressor | Compressor shell temperature | Critical |
| E121 | Compressor | Compressor overcurrent | Critical |
| E122 | Compressor | Inverter overcurrent (instantaneous) | Critical |
| E123 | Compressor | Inverter IPM/IGBT fault | Critical |
| E128 | Compressor | Inverter heatsink overtemperature | Critical |
| E130 | Compressor | Compressor startup failure | Critical |
| E131 | Compressor | Compressor over-speed | Critical |
| E132 | System | Phase reversal / Open phase | Critical |
| E134 | System | DC link overvoltage | Critical |
| E135 | System | DC link undervoltage | Critical |
| E151 | Sensor | Outdoor air temperature sensor | Info |
| E152 | Sensor | Discharge temperature sensor | Warning |
| E153 | Sensor | Suction temperature sensor | Warning |
| E154 | System | Outdoor fan motor fault | Warning |
| E156 | System | Four-way valve fault | Warning |
| E160 | System | Oil recovery fault | Warning |
| E170 | System | EEPROM fault | Critical |
| E201 | Sensor | Indoor room temperature sensor | Warning |
| E202 | Sensor | Indoor pipe (coil) sensor | Warning |
| E203 | Sensor | Indoor discharge sensor | Warning |
| E207 | Indoor | Indoor fan motor fault | Warning |
| E210 | Indoor | Indoor EEV fault | Warning |
| E213 | Indoor | Drain pump / Float switch | Warning |
| E218 | Indoor | Indoor PCB fault | Critical |
| E401 | Communication | Communication error — outdoor to indoor | Critical |
| E402 | Communication | Communication error — between outdoor units | Warning |
| E404 | Communication | Communication error — remote controller | Warning |
| E405 | Communication | Communication error — central controller | Warning |
| E416 | Communication | Address setting error | Info |
| E421 | Communication | Communication error — optional equipment | Warning |
Getting Started
Knowing what a fault code means is step one. Preventing it from happening is step two.
1. Book a Demo
See Nexus iQ monitoring a live Samsung DVM system — real fault history, real diagnostic charts, real trending data.
2. Connect Your System
A Nexus 32 controller connects via Samsung’s protocol. Installation takes under a day, requires no downtime.
3. Stop Guessing
Within 24 hours you’ll have a complete diagnostic view. Within two weeks, baseline patterns. Within a month, predictive insights.