Demirdöküm – Vaillant Three-Way Valve Motor 28BYZ-A03C 150 Ohm (Kalisto Compatible)

Three-way valve motor (step motor) is a critical actuator part that positions the three-way valve switching the combi boiler between the heating (central heating) and domestic hot water circuits. When it fails, complaints such as no switching between hot water and heating, water not heating up, fluctuating hot water or error codes may occur.

28BYZ-A03C model, with a 150 Ohm resistance value, this valve motor is preferred for compatible use in combi boilers built on the Demirdöküm and Vaillant platform, especially in Demirdöküm Kalisto series applications. Its step motor design provides precise movement and stable operation.

With its sturdy body, metal shaft output and socket connection, it allows easy installation in service work. It can be used safely as a replacement for switching problems caused by the three-way valve motor.

Product Features

• Part Type: Three-Way Valve Motor (Step Motor)
• Model: 28BYZ-A03C
• Resistance Value: 150 Ohm
• Application: Combi boiler three-way valve actuator
• Connection: Socket
• Shaft: Metal shaft

Compatibility

• Demirdöküm combi boilers (including the Kalisto series)
• Vaillant combi boilers

Fault Symptoms (Service Tip)

• No switching between central heating / hot water
• Delayed or fluctuating hot water
• Three-way valve position error / sticking
• Irregular combi boiler operation (caused by the valve motor)

Installation and Safe Use

Before installation, check the model (28BYZ-A03C) and resistance (150 Ohm) compatibility with the old part. The socket connection and shaft design must be exactly the same. Do not work on the appliance without disconnecting power. Installation by an authorized service or experienced technician is recommended.

Frequently Asked Questions

What does a three-way valve motor do?

The three-way valve motor (step motor) is the actuator part that positions the three-way valve switching the combi boiler between the central heating and domestic hot water circuits. Its step motor design provides precise movement and stable operation.

What are the symptoms of a faulty three-way valve motor?

Typical symptoms are no switching between central heating and hot water, water not heating up, delayed or fluctuating hot water, valve position errors and irregular operation caused by the valve motor.

Which combi boilers is the 28BYZ-A03C valve motor compatible with?

It is preferred for compatible use in combi boilers built on the Demirdöküm and Vaillant platform, especially in Demirdöküm Kalisto series applications.

What should I check before installing the valve motor?

Check model (28BYZ-A03C) and resistance value (150 Ohm) compatibility with the old part. Its socket connection and metal shaft output allow easy installation in service work.

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.