About Carrier fan coils
Origin: USA (Carrier). In Türkiye: Via Alarko Carrier in Türkiye; the 42CT is made in Gebze.
Carrier fan coil series we service
- 42CT
- 42DT
- 42GW
Unit types
Service highlights
- EC motor options
- Eurovent-certified products
Our services for Carrier fan coils
Carrier fan coil maintenance
Checks of filters, coil, drain pan, drainage, fan, valves and thermostat; documented periodic maintenance.
Carrier fan coil faults and repair
On-site repair of water leaks, no cooling, fans not turning, valve and controller faults.
Cleaning and filters
Chemical coil washing, drain pan disinfection, filters cut to size.
Carrier fan coil spare parts
Supply and fitting of compatible motors, valves, thermostats, pumps and other parts.
Carrier fan coil error codes
Carrier 42GW cassette – HDB control board
The red LED on the board flashes as many times as the fault number (0.5 s on / 0.5 s off, followed by a 5 s pause).
| Code / indication | Meaning | What to do |
|---|---|---|
| 2 flashes | Air temperature sensor fault | Check the sensor and connector; replace if necessary. |
| 3 flashes | Water (changeover) sensor fault | Check the water sensor's connection and its position on the pipe. |
| 4 flashes | Cold draft thermistor fault | Check or replace the thermistor. |
| 5 flashes | Condensate pump fault | Clean the drain line and float switch, and check the pump. |
| 6 flashes | Electric heater configuration error | Correct the board settings (DIP switches / parameters). |
| 7 flashes | Board memory (EEPROM) error | The control board must be replaced. |
| 8 flashes | Chilled beam configuration error | Correct the configuration. |
Carrier 42N series – electronic control
Faults are indicated by the colors of the LEDs on the board.
| Code / indication | Meaning | What to do |
|---|---|---|
| Red LED flashing | Sensor fault: room sensor or water temperature sensor faulty or short-circuited | Measure the sensors and replace the faulty one. |
| Yellow LED flashing | Configuration error: central changeover signals active at the same time | Correct the wiring and settings. |
Carrier 42TPM
If there is more than one fault, the codes are shown in sequence.
| Code / indication | Meaning | What to do |
|---|---|---|
| E1 | Room sensor fault | Check or replace the sensor. |
| E2 | Coil sensor fault | Check or replace the sensor. |
Sources: document 1, document 2, document 3
Common thermostat warnings
Warnings shown on Siemens RDF series thermostats, which are often used with Carrier fan coils:
| Indication | Meaning | What to do |
|---|---|---|
| AL1 | External fault input X1 active (e.g. drain alarm) | Check the device connected to input X1. |
| AL2 | External fault input X2 active | Check the device connected to input X2. |
| FIL | Filter cleaning reminder | Clean the filter and reset the warning. |
| Dew (condensation) symbol | Condensation detected in the room, cooling stopped | Check humidity and water temperature. |
Is your Carrier fan coil showing a code?
Send a photo of the controller display and the unit's rating label and we will interpret it right away.
Carrier fan coil controllers and thermostats
CRC
Wired · for 42GW cassettes
IR remote control
Wireless · for 42GW cassettes
NTC control
Network-capable · Integration with central systems
Type A and B controls
Electronic control · 42N series
In addition to these controllers, we replace faulty or outdated thermostats with new models suited to the unit's 2/4-pipe configuration, valve type and motor speeds: mechanical, digital, weekly programmable and Modbus / BACnet / KNX networked options. Thermostat options →
Carrier fan coil spare parts
Carrier fan coil motor
Compatible part supply and fitting
Carrier capacitor
Compatible part supply and fitting
Carrier fan wheel
Compatible part supply and fitting
Carrier motorized valve
Compatible part supply and fitting
Carrier actuator
Compatible part supply and fitting
Carrier thermostat
Compatible part supply and fitting
Full spare parts catalog (28 parts) →
Carrier fan coil service in Ankara
We service Carrier fan coils on-site in every district of Ankara. We prepare bulk maintenance plans for office towers, hospitals, hotels, schools, shopping malls and residential complexes. For Carrier units outside Ankara, we start with a pre-diagnosis from photos and videos, followed by a scheduled visit with the required parts.
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Trane fan coil serviceFrequently asked questions
Do you service Carrier fan coils on-site in Ankara?
Yes. Our base is in Etimesgut; we carry out on-site maintenance, fault repair and part replacement on Carrier fan coils in every district of Ankara. For Carrier units outside Ankara we provide scheduled service across Türkiye.
Are you the authorized Carrier service?
No. YOİ Mühendislik is an independent service holding the TSE Service Adequacy Certificate (HYB No: 12850); we service all brands, including Carrier, independently of the manufacturer. For units still under warranty, we recommend checking the manufacturer's terms first.
What does a Carrier fan coil error code mean?
This page lists Carrier fan coil codes compiled from manufacturer documentation. Codes may vary by model and controller; send us a photo of the code on the display and we will interpret it.
Are Carrier fan coil spare parts available?
For parts such as motors, capacitors, motorized valves, actuators, thermostats, drain pans, condensate pumps, filters and fan wheels, we supply original parts that fit Carrier units or equivalents whose technical ratings match exactly. A photo of the rating label is enough.
How often should Carrier fan coils be serviced?
A full service at least twice a year, before the cooling and heating seasons; filter checks are recommended every 1–3 months depending on usage.