Transformer For Junkers Boiler ZWC 28-3 MFK - Code 8 747 201 379
The transformer for the Hahn boiler, reference 8747201379, generates the spark necessary to ignite the burner. When it fails, the boiler attempts to start unsuccessfully, causing it to lock out. This part is compatible with several models, including those from the Junkers ZWC range, such as the Junkers ZWC 28-3 MFK, among others. A technician must confirm through diagnosis whether it is necessary to replace the transformer when ignition problems or failed start attempts occur.
- Type of part
- Transformers
- Status
- Refurbished
- Catalogue reference
- 8717201052
- Warranty
- 1 year
Junkers boilers compatible with reference 8717201052
Ignition transformer with reference 8717201052. Five confirmed compatibilities: 14-3 and 24-3.
Proven compatibility
| Boiler model | Family | Verification |
|---|---|---|
| Junkers 14-3 | ZSB | Contrasted |
| Junkers 24-3 | ZSC | Contrasted |
| Junkers 28-3 | ZWB | Contrasted |
| Junkers 24-3 MFK | ZWC | Contrasted |
| Junkers 28-3 MFK | ZWC | Contrasted |
Can't see your model or have questions? The printed reference takes precedence. How to check it · Send us a photo via WhatsApp.
How to check if ref. 8717201052 is the part for your boiler
The part reference, model, and equipment revision must be verified against the manufacturer's documentation.
- Find the reference printed on the installed part and check whether it matches the catalogue reference 8717201052. If it is not visible, do not identify the part from its shape alone.
- Check the full boiler model on its data plate and look for it in the model associations on this page.
- Compare the connections and physical body with the original part before installation.
- If anything is unclear, send us a photo of the marking via WhatsApp before placing your order.
Symptoms that require diagnosis in the ignition transformer 8717201052
The ignition transformer generates the high voltage for the spark of the electrodes. These are the typical symptoms and what to do:
Common symptoms and faults
- 01
The fan does not start or stops mid-cycle and the boiler locks out.
Cause: One of the secondaries of this transformer powers the fan circuit or the gas valve; if that output fails, the component loses power.
Measure the voltage on both secondaries of the transformer with the boiler running and compare it with what is indicated on the label before replacing it.
- 02
The boiler starts but shuts down with a fault code related to the fan or the gas valve.
Cause: Without the proper voltage in that winding, the control unit interprets that the component is not responding and locks out for safety.
First, check the wiring and the connector of that transformer output; a loose contact gives the same fault code.
- 03
The display and indicators are working well, but the boiler does not start the burner.
Cause: The other low voltage winding can only power the logic of the PCB, which remains operational even if the power section fails.
Check with the multimeter if there is voltage in the higher power secondary (25V) while the electronics one (9V) is working.
- 04
Buzzing or vibrating noise in the transformer area, especially when starting up.
Cause: A double-wound transformer that starts to fail usually vibrates more when subjected to the starting load.
Check that the transformer mounting screws are tight; a loose assembly causes the same noise without the part being damaged.
These symptoms can have more than one cause. If your boiler displays a fault code, send it to us via WhatsApp along with a photo of the labeling, and we'll tell you if this is the part.
Ignition transformer datasheet Junkers 8717201052
- Catalogue reference
- 8717201052
- Uniclima internal SKU
- TJZWC31
- Brand
- Junkers
- Type of part
- Transformers
- Units in stock
- 3 units
- Status
- Refurbished
- Warranty
- 1 year
- Shipping
- Delivery time shown at checkout
- Return
- 14 days
Part data and available documentation
Contrast the label codes, PCB, and revision with the installed part; they are not necessarily equivalent references.
- Primary voltage
- 230V 50-60Hz, terminals 5-7
- Printed code
- 8 747 201 379
- Additional label code
- V 17976
- Thermal class
- 70°C/B
- Secondary I
- 25V, 34VA, terminals 10-11
- Secondary II
- 9V, 4.5VA, terminals 12-13
Manuals and technical documentation
Official documentation of the boiler, useful for locating the part and cross-referencing the fault codes.
- Junkers 28-3 manual (PDF) Document © Junkers, provided as a technical reference.
Frequently asked questions about the ignition transformer 8717201052
Is this transformer compatible with the Junkers ZSB 14-3 boiler?
What are the boiler models compatible with this transformer?
What are the characteristics of the transformer of the Junkers ZWC 28-3 MFK?
What thermal class does this transformer have?
Are there documented fault codes for this transformer?
