Refurbished Junkers Junkers

Junkers PCB 8748300270 · For ZW 20-1 AME 23

Application for the exact variant pending confirmation. It is the control and management PCB of the boiler functions.

Type of part: Junkers
Status: Refurbished
internal SKU: PLC212
Warranty: 1 year

VAT included Stock · 10 units

Compatibility

Compatible Junkers boilers

Junkers. 0 verified compatibilities. There are another 6 models that we are still checking.

Models pending verification

These models are associated with this reference, but we have not finished verifying them yet, so we do not consider them compatibleIf your boiler is one of them, send us a photo of the part you are going to replace and we will verify it before you purchase.

Junkers Novatherm ZW 20 AME	Junkers	Unconfirmed
Junkers Novatherm ZW 20 KE	Junkers	Unconfirmed
Junkers Novatherm ZS 20 AME	Junkers	Unconfirmed
Junkers Novatherm ZW 20-1 KE	Junkers	Unconfirmed
Junkers Novastar ZW 20-1 AME 31, ZW 20-2 AME and ZW 20-2 KE	Junkers	Unconfirmed
Junkers ZW 20-1 AME 23	Junkers	Unconfirmed

Can't see your model or have questions? The printed reference takes precedence. How to check it · Send us a photo via WhatsApp.

Guide

How to check if it is the part for your boiler

The part reference, model, and equipment revision must be verified against the manufacturer's documentation.

Look for the code 8 748 300 270 (also written as 8748300270) on your PCB. This technical sheet is for that reference.
Check the second marked code, 874 501 087, in the NEC JAPAN integrated circuit with 026-EF01/00.
If your PCB has 8 748 300 371, it is the official breakdown code for the ZW 20 AME and ZW 20 KE: send us a photo from Contact to compare it.
Look at the model on the boiler's rating plate: the ZW 20-1 AME 23 is registered.
if they match, call us at 911 17 77 77 with the model of your boiler.

Diagnosis and fault codes

Symptoms that require diagnosis in the junkers

Common symptoms and faults

01
The boiler shuts down or locks out with fault code EA.
Cause: No flame detected: lack of gas, dirty ignition electrode, or poor ionization.
Press the reset button once. If it repeats, have a technician check the gas, the electrode, and its cable.
02
The red LED blinks once every 2 seconds and the burner does not start.
Cause: Moisture on the PCB, control electrode shorted to ground or NTC sensor.
Have a technician check it: verify the humidity and the condition of the PCB before replacing it.
03
The red LED flashes once per second: there is a spark, but the burner does not ignite and the boiler locks out.
Cause: Dirty ionization electrode or poor ionization, weak ignition or lack of gas.
Have a technician check it: the electrode and ignition are tested before replacing the PCB.
04
The red LED flashes twice per second and the boiler is locked.
Cause: Overtemperature: temperature limiter, thermal sensor or seized pump.
Have a technician check: circulation, the pump, and the thermal sensor.

Junkers fault codes that require diagnosis

Code	Fault	Technical checks
EA	There is no ionization current: the boiler does not detect the flame and shuts down or locks out.	Press reset once. If it repeats, have a technician check the gas, the ignition electrode, and the ionization cable. If all that is fine, point to the PCB.
F0	Internal fault of the PCB or its connections.	Check that the contacts on the PCB are properly connected. If the fault code persists, the PCB is the suspected part: have it checked by a technician.
FA	It continues to detect flame after closing the gas.	Have a technician check the wiring of the gas valve and the electrode. If the wiring is fine, it points to the PCB.
A7	The NTC sensor for domestic hot water is faulty.	Have a technician check the sensor and its connection to the PCB. The PCB is suspected if the sensor is functioning properly.
E2	The heating flow NTC sensor is faulty.	Have a technician check the heating sensor and its cable. The PCB is suspected if the sensor is fine.

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.

Technical data

Technical sheet: Junkers

Uniclima internal SKU: PLC212
Brand: Junkers
Type of part: Junkers
Units in stock: 10 pcs
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.

Inventory — Integrated circuit subcomponent: NEC JAPAN; 026-EF01/00; 8744 501 087; 9808KY002
Inventory — Fuse: 2.0 A
Inventory — Subcomponent condenser: 0.47 μF; 400 V
Inventory — Application indicated in inventory: ZW 20 1 AME 23
Official list data — PCB in the parts list: 8 748 300 371 («Control board»), pos. 7 · Official list ZS/ZW 20 AME and ZW 20 KE
Official list data — Fuses of the control panel: T 2 A (8 744 503 011) · T 2.5 A (1 904 521 342) · Official list ZS/ZW 20 AME and ZW 20 KE
Identification — Marked code: 8 748 300 270
Identification — Marked code: 874 501 087
Inventory data — Integrated circuit subcomponent: NEC JAPAN; 026-EF01/00; 8744 501 087; 9808KY002
Inventory data — Fuse: 2.0 A
Inventory data — Subcomponent condenser: 0.47 μF; 400 V
Inventory data — Application indicated in inventory: ZW 20 1 AME 23
Pending applications to verify: ZW 20 1 AME 23 — noted compatibility; pending confirmation by variant. It cites Junkers Novatherm ZW20-1AME and ZW20-1KE for 8748300371/ex8748300270; it warns that it may vary by serial number. Commercial declaration pending.
Registered equivalents and substitutions: Registered application: 8748300371 as a substitute for 8748300270. It is a commercial cross, pending documentation from the manufacturer and the serial number.

Before purchasing

To confirm: signs of failure for the PCB 8748300371 include the boiler not igniting or being unresponsive, erratic fault codes on the display, stuck relays or burnt traces, and unexpected resets.
Junkers Novatherm ZW 20 AME — Official parts list + with reference 8748300371
To confirm: Junkers Novatherm ZW 20 KE — Official parts list + with reference 8748300371
Junkers Novatherm ZS 20 AME: official parts list (8 748 300 371)
Junkers Novatherm ZW 20-1 KE — Technical sheet: Italian «ex 8748300270» + compatible with reference 8748300371
To confirm: Junkers Novastar ZW 20-1 AME 31, ZW 20-2 AME and ZW 20-2 KE — with reference 8748300371
Do not confuse: 8 717 207 452 — "Control unit" / "Switch box", item 1 of the official breakdown of the ZW 20 AME and ZW 20 KE — It is a different position than the PCB ("Leiterplatte").
Do not confuse: 87483002460 — Reference for the PCB of the ZW20-1AME23 Novastar "atmospheric" — It is a different reference. Registered confirmation: the ZW 20-1 AME 23 with the 8748300270.
The change 8748300270 → 8748300371 (to be confirmed) comes from an Italian source (sheet no. 1407: ), whose independence is not verified. An Italian breakdown of the ZW 20-1 AME states "ex 270-0" next to 8 748 300 371, without writing the complete code.
PCB 8748300270 identified by. The official breakdown provides 8748300371 for the ZW 20 AME and KE; only Italian sources (sheet no. 1407, independence not verified) list it as a substitute.
Pending registered applications to confirm by model, variant, or programming: Junkers ZW 20-1 AME 23.

Frequently Asked Questions

Frequently asked questions: junkers

How do I recognize the PCB 8748300270?

It is marked 8 748 300 270 and 874 501 087. The 874 501 087 is the marking of the NEC JAPAN integrated circuit (026-EF01/00; 9808KY002), according to the workshop inventory. Compare your PCB with these codes before deciding.

Is it compatible with my Junkers ZW 20-1 AME 23?

The compatibility of this variant is pending confirmation. Registered: for the ZW 20-1 AME 23. Additionally, an Italian parts list for the Novatherm ZW 20-1 AME, the Italian sheet No. 1407 and Spanish ones indicate that for that model the PCB is 8748300371.

Are the 8748300270 and 8748300371 PCBs the same?

The official breakdown of the ZW 20 AME and ZW 20 KE only mentions 8 748 300 371 as the PCB ("Leiterplatte"). The Italian version titles it "8748300371, ex 8748300270": the 371 would be the later code. It is provided by an Italian source (sheet no. 1407: ), whose independence is not verified: to be confirmed. The PCB of this sheet is 8 748 300 270.

Does the PCB change if my ZW20-1AME23 is sealed or atmospheric?

Registered confirmation: the PCB 8 748 300 270 for the ZW 20-1 AME 23, regardless of versions. Some provide another code for the sealed version (8748300371) and another reference for the atmospheric version (87483002460). If your PCB code is not 8 748 300 270, send us a photo of the rating plate from Contact or call us at 911 17 77 77.

What fuse does the PCB use?

this PCB has a 2.0 A fuse. The official list includes a T 2 A (8 744 503 011) and a T 2.5 A (1 904 521 342) as spare parts for the control board, without specifying which one is used in the PCB. If it blows, replace it with the same value and check the cause beforehand.

Is it compatible with other models ZW 20 that are not the ZW 20-1 AME 23?

The compatibility of this variant is pending confirmation. It is not confirmed. With the code 8748300371, the official breakdown lists the PCB for the Novatherm ZW 20 AME, ZS 20 AME, and ZW 20 KE; the Italian sheet adds the ZW 20-1 KE; and they also list the ZW 20-1 AME 31 and the ZW 20-2 AME and KE. Send us a photo of the label and the specifications plate from Contact, or call 911 17 77 77.

Who should install this PCB?

A qualified technician: the boiler operates with gas and mains voltage. Disconnect it from the mains before touching the PCB and do not replace the fuse with one of a different rating.

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Junkers PCB 8748300270 · For ZW 20-1 AME 23