Chunhui WV20M55 320100164 Combi Boiler 3-Way Valve Stepper Motor 7.5mm (ECA, Baymak, Biasi Compatible)

A high-performance 3-way valve stepper motor, one of the parts most frequently used by service companies for faults in the diverter that switches between central heating and domestic hot water in combi boilers. Fully compatible with ECA, Baymak and Biasi Compact series combi boilers, this spare part lets you carry out fast, practical and guaranteed repairs during the busy winter season.

Key Technical Specifications and Label Values

• Brand and Type: Chunhui / WV20M55 (Long-life winding design of original equipment manufacturer quality)
• Reference / OEM Code: 320100164
• Operating Voltage: 220V / 50Hz (Fully compatible with the standard boiler PCB output voltage, stable switching)
• Stroke (Travel): 7.5mm (Fits the brass or plastic 3-way valve assemblies of the listed brands precisely, without play)
• Maximum Operating Temperature (T70): Operates without problems at ambient temperatures up to 70°C inside the closed boiler casing.
• Protection Class: IP40 (Outer housing protected against solid objects larger than 1mm)

Technician Tips and Field Installation Warnings

• Before fitting the new stepper motor, always check whether there is a water leak at the push rod (piston) of the 3-way valve assembly. The cause of failure of the old motor is usually water leaking from this area. If there is a leak, first replace the O-ring or repair kit; the motor's insulation (IP40) is not suitable for contact with liquid.
• When connecting the motor's 3-pin socket, check whether the cable connector from the boiler PCB is oxidized. Poor contacts can cause the stepper motor to turn half a turn and get stuck or lose its position.
• Thanks to the 7.5mm stroke, it fits directly into its seat without an extra adapter, and installation is completed within seconds by fitting the clip.

Frequently Asked Questions

What does the 3-way valve stepper motor do?

It moves the 3-way valve (diverter) that switches between central heating and domestic hot water in the combi boiler. It is one of the spare parts most frequently used by service companies for diverter faults.

Which combi boilers is this stepper motor compatible with?

It is compatible with ECA and Baymak combi boilers and the Biasi Compact series. Thanks to its 7.5mm stroke (travel) (Some sellers incorrectly list this dimension as the shaft diameter; 7.5 mm is not the diameter of the shaft but its travel distance.) it fits the brass or plastic 3-way valve assemblies of these brands without play.

What are the equivalent / original (OEM) codes of the stepper motor?

It is an equivalent of the parts with reference codes 320100164 and WV20M55. The Yedepa product code is CVM03; it operates at 220V / 50Hz.

What should be checked before fitting the new stepper motor?

First, check whether there is a water leak at the push rod (piston) of the 3-way valve assembly; the cause of failure of the old motor is usually water leaking from there. If there is a leak, the O-ring or repair kit should be replaced first, because the motor's IP40 insulation is not suitable for contact with liquid.

Can I buy regularly with an invoice as a service company/technician?

Yes, all our sales are invoiced. All orders, including those from service companies and technicians, are placed directly through our website.

How do I track my shipment after ordering?

Your shipment tracking number is sent to your e-mail and phone after ordering; you can follow its status in the “Where Is My Shipment?” section.

Can I return or exchange the product?

Yes. Under Consumer Protection Law No. 6502 you have the right of withdrawal/return within 14 days of delivery. To avoid ordering the wrong model, we recommend that you verify compatibility before ordering. Details are on our “Delivery, Returns and Exchanges” page.

What payment and instalment options are available?

You can pay by debit/credit card and Tosla, and take advantage of instalment/credit options through Fibabanka and Akbank. Current options are listed on our “Payment Options” page.

Where is Yedepa located and how is delivery made?

Yedepa is an e-commerce site; orders are placed through yedepa.com and shipped to your address by courier from our warehouses across Turkey and from our contracted suppliers. Our head office is at Cennet Mah. 2. Yavuz Selim Cad. No:68/A, Küçükçekmece / İstanbul.