Part selection also depends on the unit type; for the differences between cassette, concealed ceiling and floor-standing units, see our fan coil types guide.
Fan and motor assembly
Fan coil motor (AC 3-speed / EC)
Drives the centrifugal blower that pushes air across the coil. Older units use 3-speed AC motors; newer ones use energy-efficient EC motors.
Failure symptoms: humming, fan not turning, overheating, thermal cut-out tripping, bearing noise, stuck on one speed.
Motor capacitor
Provides the phase shift a single-phase motor needs to start and run. Cheap, but one of the parts that fails most often.
Failure symptoms: motor hums but will not start, turns when pushed by hand, low speed, capacitor swollen or leaking.
Speed transformer / speed selector
Runs a single-speed motor at several speeds using different voltage taps.
Failure symptoms: some fan speeds not working, humming or a burning smell from the transformer.
Blower wheel / impeller
Draws air in and discharges it under pressure. Airflow drops as it gets dirty, and it becomes noisy if it loses balance.
Failure symptoms: vibration, imbalance, low airflow from dirt on the blades, cracked or broken blades.
Blower housing (scroll)
Directs the air from the wheel and converts it into pressure.
Failure symptoms: broken clips, rubbing noise, air leakage.
Motor mount and anti-vibration pads
Hold the motor in place and stop vibration passing into the casing and ceiling.
Failure symptoms: rattling, vibration in the casing, motor shifting out of position.
Valves and water side
2-way motorized valve body
Opens or shuts off the water flow to the coil.
Failure symptoms: water does not shut off (constant heating/cooling), no water flow, stem leak, limescale.
3-way motorized valve / 4-port valve
Diverts water either to the coil or to the bypass line, keeping the system flow rate constant.
Failure symptoms: room always cold or hot, constant flow through the bypass, leaks.
Valve motor / actuator
Opens, closes or modulates the valve according to the thermostat signal.
Failure symptoms: valve does not open, position indicator does not move, burnt thermoelectric element, stripped gears.
Balancing valve (static / pressure-independent)
Ensures each fan coil receives its design flow rate, so that distant units do not get too little water and nearby ones too much.
Failure symptoms: some units heating or cooling poorly, valve noise.
Ball valve
Isolates the unit from the pipework during servicing.
Failure symptoms: stiff handle, does not shut off fully, gland leak.
Strainer (Y-type)
Protects the valve and coil from sediment and debris in the pipework.
Failure symptoms: low flow, clogged mesh, unit heating and cooling weakly.
Automatic air vent
Releases air trapped in the coil.
Failure symptoms: gurgling noise, half of the coil staying cold, dripping from the air vent.
Fan coil flexible hose
Connects the unit to the pipework flexibly and without vibration, making installation easier.
Failure symptoms: leaking fittings, condensation on the insulation, corroded braiding.
Controls and electrics
Room thermostat (mechanical, digital, BMS)
Controls the fan speed and the valve according to room temperature.
Failure symptoms: blank display, fan speed will not change, wrong temperature reading, stuck relay.
Room / return air sensor
Measures the temperature used by the control board.
Failure symptoms: unit never stops or never starts, error code.
Water temperature sensor (minimum water / changeover)
Stops the fan, or switches the mode automatically, if the water is not hot or cold enough.
Failure symptoms: fan never starts, no mode changeover.
Control board
Distributes thermostat commands to the motor speeds and the valve; on electronically controlled units it generates the error codes.
Failure symptoms: no response at all, burn marks, relay clicking, tripping fuse, error code.
Relays and terminals
Carry the speed and valve signals; loose or burnt connections cause failures.
Failure symptoms: intermittent operation, overheated or blackened terminals, loss of a speed.
Fan coil controller and thermostat types
The part that controls the fan coil on the user side is the controller or room thermostat. When it is replaced, the new controller must match the unit's motor type, pipe system and valve arrangement.
| Type | Features | Where is it suitable? |
|---|---|---|
| Mechanical thermostat | Rotary setting, 3-speed fan switch, heating/cooling selector | Simple units with 3-speed AC motors |
| Digital thermostat | Display, precise temperature control, automatic fan speed; weekly programming on some models | Offices, hotels, homes; replacing mechanical thermostats |
| EC motor compatible thermostat | Stepless speed control via a 0–10 V fan output | Fan coils with EC motors |
| Wi-Fi / smart thermostat | Remote control and programming from a phone | Homes, villas, small offices |
| Wireless (IR) remote control | Works with the receiver on the unit; usually specific to the unit's brand | Cassette and wall-mounted units |
| On-unit control panel | The controls are located directly on the unit casing | Cabinet floor-standing and wall-mounted units |
| Networked thermostat and central panel | Connects to building automation via Modbus, BACnet or KNX; many units are managed from a single point | Hotels, hospitals, office towers, public buildings |
Controller wiring and connection
- The number of wires between the thermostat and the unit depends on the fan speeds, the valve and the summer/winter signal; the terminal layout of the old and new controller may differ.
- For networked controllers, the cable type and maximum length recommended by the manufacturer apply.
- Before the controller is replaced, the terminals the old wires are connected to are photographed.
- The connection must be made with the power isolated and according to the unit's wiring diagram.
Brand-specific controllers
On some brands the controller works together with the unit's own control board and is brand-specific. For these units an original controller or a solution compatible with the board is chosen; on simple 3-speed units, general-purpose thermostats such as Siemens, Honeywell or Schneider Electric can be used. Controller sections on our brand pages: Daikin, Aermec, Alarko Carrier, Galletti, McQuay, Aldağ.
Guides (in Turkish): thermostat wiring diagram, Wi-Fi smart thermostat, Siemens RDF thermostat, Daikin fan coil controller, Aldağ thermostat and controller, remote control not responding, thermostat prices.
Drainage
Condensate drain pan
Collects the condensate that drips from the coil during cooling.
Failure symptoms: overflowing, stains on the ceiling, odour, rust or holes.
Condensate (drain) pump
Pumps the condensate away where it cannot drain by gravity.
Failure symptoms: pump not running or running constantly, overflow, unit stopped by the alarm.
Float switch / overflow alarm
Starts the pump or stops the unit when the water level in the pan rises.
Failure symptoms: alarm permanently active, pump does not kick in.
Air side and casing
Fan coil filter
Protects the coil and fan from dust and improves indoor air quality.
Failure symptoms: reduced airflow, dirty coil, odour.
Coil (heat exchanger)
Transfers heat between the water and the air.
Failure symptoms: water leaks, crushed and dirty fins, frost cracks, loss of capacity.
Electric heater
Used in some fan coils as an additional or sole heat source.
Failure symptoms: no heating, safety thermostat tripping, burning smell.
Cassette panel and grille
Distributes air in four directions on cassette units.
Failure symptoms: broken grille, panel that will not close, yellowed surface.
Louvre (swing) motor
Moves the air discharge louvres on cassette and wall-mounted units.
Failure symptoms: louvres not moving, grinding noise.
Plenum, diffuser and duct connection
Carries air from a concealed ceiling unit into the ductwork and grilles.
Failure symptoms: air leakage, noise, condensation.
Pipe and valve insulation
Prevents condensation and heat loss on chilled water pipes and valves.
Failure symptoms: sweating and dripping on pipes, valves or the ceiling.
Can't find your part in the list?
Send us a photo; we also source and supply parts that are not listed here.
Commonly used spare part brands
Alongside original parts, products from the manufacturers below are widely used in fan coils for components such as valves, actuators, thermostats, motors and pumps. We select parts according to your unit's technical values.
Watts
Motorized valve bodies and thermoelectric / electromechanical actuators
Siemens
VVP47 / VXP47 valves, STA/STP actuators, RDF / RDG fan coil thermostats
Honeywell
VC series zone valves and actuators, fan coil thermostats
Belimo
ZoneTight QCV valves and CQ actuators
Danfoss
AB-QM pressure-independent balancing and control valves, TWA thermal actuators
Schneider Electric
SpaceLogic SE8000 fan coil thermostats
Smallart
Mechanical and digital fan coil thermostats
ebm-papst
EC fans for fan coil applications
Ziehl-Abegg
EC motor fans
Fergas
Fan coil fan motors and blower wheels
Ducati Energia
Motor capacitors
Euromotors
Fan coil speed transformers
Caleffi
Automatic air vents
Sauermann
Mini condensate pumps
Aspen Pumps
Mini condensate pumps
Charles Austen (Blue Diamond)
Tank-type condensate pumps
DDC-Tech
Fan coil valve bodies and actuators
E.C.A.
Motorized fan coil valve sets
Fan coil spare parts by brand
Choose your unit's brand; the brand page covers its series, error codes and controllers.
Aldağ fan coil service
Üntes fan coil service
Daikin fan coil service
Alarko Carrier fan coil service
Carrier fan coil service
Form fan coil service
Systemair fan coil service
Mitsubishi Electric fan coil service
Climaveneta fan coil service
Arçelik fan coil service
Ventas fan coil serviceTeknogenTeknogen fan coil service
Trane fan coil service
York fan coil service
Aermec fan coil service
Galletti fan coil serviceWhat to send for part matching
To find the right part first time, send the information below together with photos of the rating plate and the old part. Leave out any values you don't know; the label on the part itself is often enough.
| Part | What to send |
|---|---|
| Fan motor | Motor label code; single or double shaft; shaft diameter and length; body diameter; number of AC speeds or EC; power (W); direction of rotation; supply voltage; number and colours of wires |
| Capacitor | Capacitance (µF), voltage (V), connection type (wired or plug-in), body size |
| Motorized valve body | Connection size (DN / inch), Kvs value, 2-way or 3-way (4-port), thread type, body brand |
| Actuator (valve motor) | Supply voltage (230 V / 24 V), normally closed (NC) or normally open (NO), on/off or modulating (0–10 V), connection adapter, cable length |
| Thermostat / controller | 2-pipe or 4-pipe; number of fan speeds or EC (0–10 V); supply (230 V / 24 V); valve output (on/off / 0–10 V); summer/winter changeover (manual / automatic); flush or surface mounted; communication requirement (Modbus, BACnet, KNX) |
| Condensate pump | Pump model, flow rate, lift height, float and alarm contact, supply voltage |
| Control board | Code and label on the board, photos of both sides of the board, connected controller model |
| Filter | Width × height × thickness, filter class (G2 / G3 / G4), frame type |
| Coil | Number of rows, fin length and height, tube diameter, connection side (right / left), 2-pipe or 4-pipe |
| Blower wheel | Wheel diameter and width, hub (shaft) diameter, direction of rotation, number of scrolls |
How to order
| Step | What happens |
|---|---|
| 1. Photo | You send a photo of the unit's rating plate and the part to be replaced. |
| 2. Matching | We identify the original or equivalent part from the make, model and technical values. |
| 3. Quotation | Price, lead time and any difference for an equivalent part are sent to you in writing. |
| 4. Delivery / fitting | The part is shipped by courier, or fitted and tested by our team. |
Frequently asked questions
What should be checked when replacing a fan coil motor?
Power (W), number of speeds, rpm, shaft diameter and number of shafts, direction of rotation and capacitor value must all match. For EC motors, compatibility of the control signal (0–10 V / PWM) is also checked.
How can I tell whether the motorized valve or the actuator has failed?
If water flows when the actuator is opened manually, the problem is usually the actuator. If water does not flow even when opened manually, the valve body may be blocked or seized.
Can I replace the thermostat with a different brand?
Yes. A thermostat of a different brand can be used as long as the 2/4-pipe configuration, valve type, motor speeds and supply voltage are compatible.
How is a condensate pump selected?
It is selected according to flow rate (l/h), discharge head and the unit's cooling capacity. If it has an alarm contact, it should be connected to the unit's control circuit.
Do you ship parts outside Ankara?
Yes, we ship parts by courier anywhere in Turkey.