Gas Valve ZWC/ZWN Ref. 8747003700
The gas valve ZWC/ZWN Ref. 8747003700 from SIT regulates and allows the flow of gas to the burner according to the indications of the boiler's PCB. When it fails, the boiler may not ignite, experience flame lockouts, or have modulation issues. This can manifest with faults such as FA, which indicates that a flame is still detected after the gas has been disconnected, or d7, which signals a fault in the regulating valve. This valve is compatible with models such as ZWC 24/28-1 MFA, ZSC 24-3 MFA, and ZWN 24-7 AE, among others. It is recommended to replace it if the mentioned symptoms occur or during the preventive maintenance of the boiler.
VAT included
Consult via WhatsAppJunkers boilers compatible with reference 8747003700
Gas valve with reference 8747003700. 31 verified compatibilities: ZWC 24/28-1 MFA and ZWC 24/28-1 MFK.
Proven compatibility
| Boiler model | Family | Verification |
|---|---|---|
| Junkers ZWC 24/28-1 MFA | Ceraclass Excellence / Comfort (ZWC) | Contrasted |
| Junkers ZWC 24/28-1 MFK | Ceraclass Excellence / Comfort (ZWC) | Contrasted |
| Junkers ZWC 24/28-3 MFA | Ceraclass Excellence / Comfort (ZWC) | Contrasted |
| Junkers ZWC 24/28-3 MFK | Ceraclass Excellence / Comfort (ZWC) | Contrasted |
| Junkers ZWC 24-1 MF2A | Ceraclass Excellence / Comfort (ZWC) | Contrasted |
| Junkers ZWC 24-1 MF2K | Ceraclass Excellence / Comfort (ZWC) | Contrasted |
| Junkers ZWC 28-1 MF2A | Ceraclass Excellence / Comfort (ZWC) | Contrasted |
| Junkers ZWC 28-1 MF2K | Ceraclass Excellence / Comfort (ZWC) | Contrasted |
| Junkers ZWC 28/32-1 MFA | Ceraclass Excellence / Comfort (ZWC) | Contrasted |
| Junkers ZWC 30/30-3 MFA | Ceraclass Excellence / Comfort (ZWC) | Contrasted |
| Junkers ZWC 35/35-3 MFA | Ceraclass Excellence / Comfort (ZWC) | Contrasted |
| Junkers ZSC 24-3 MFA | Ceraclass Excellence (ZSC - heating only) | Contrasted |
| Junkers ZSC 24-3 MFK | Ceraclass Excellence (ZSC - heating only) | Contrasted |
| Junkers ZSC 28-3 MFK | Ceraclass Excellence (ZSC - heating only) | Contrasted |
| Junkers ZSC 30-3 MFA | Ceraclass Excellence (ZSC - heating only) | Contrasted |
| Junkers ZSC 35-3 MFA | Ceraclass Excellence (ZSC - heating only) | Contrasted |
| Junkers ZC 24-1 MFA | Cerastar / Ceraclass (ZC - heating only) | Contrasted |
| Junkers ZC 24-1 MFK | Cerastar / Ceraclass (ZC - heating only) | Contrasted |
| Junkers ZC 24-1 MF2A | Cerastar / Ceraclass (ZC - heating only) | Contrasted |
| Junkers ZC 28-1 MFA | Cerastar / Ceraclass (ZC - heating only) | Contrasted |
| Junkers ZC 28-1 MFK | Cerastar / Ceraclass (ZC - heating only) | Contrasted |
| Junkers ZWE 23-4 A | Eurostar / Cerastar (ZWE / ZWSE) | Contrasted |
| Junkers ZWE 24-4 HA | Eurostar / Cerastar (ZWE / ZWSE) | Contrasted |
| Junkers ZWE 24-4 HK | Eurostar / Cerastar (ZWE / ZWSE) | Contrasted |
| Junkers ZWE 28-4 HA | Eurostar / Cerastar (ZWE / ZWSE) | Contrasted |
| Junkers ZWSE 23-4 MFK | Eurostar / Cerastar (ZWE / ZWSE) | Contrasted |
| Junkers ZWSE 28-4 MFA | Eurostar / Cerastar (ZWE / ZWSE) | Contrasted |
| Junkers ZWSE 28-5 MFA | Eurostar / Cerastar (ZWE / ZWSE) | Contrasted |
| Junkers ZWSE 35-6 MFA | Eurostar / Cerastar (ZWE / ZWSE) | Contrasted |
| Junkers ZWN 24-7 AE | ZWN | Contrasted |
| Junkers ZWN 24-7 KE | ZWN | 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. 8747003700 is the part for your boiler
What determines it is not the boiler model, but the reference printed on the part you already have installed.
- Find the reference printed on the installed part and check whether it matches the catalogue reference 8747003700. If it is not visible, do not identify the part by 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 and faults that the gas valve 8747003700 resolves.
The gas valve regulates and modulates the gas flow to the burner. These are the typical symptoms and what to do:
Common symptoms and faults
- 01
The boiler does not ignite, or it locks up as soon as you try to start it.
Cause: One of the solenoid valves of the gas valve does not open and the control board does not detect a flame, so it cuts off the attempt.
Check that power is reaching the gas valve at the moment of startup and that the ignition electrode is sparking before replacing it.
- 02
The flame goes up and down by itself, or it doesn't reach the power you request.
Cause: The valve modulator does not properly regulate the gas flow to the burner.
Check that the modulation signal is coming from the PCB and that the gas inlet filter is not dirty.
- 03
It smells like gas near the boiler, even when it is turned off.
Cause: Loss of tightness in the body of the gas valve or in its seals
Locate the exact point with leak detection spray and turn off the gas before touching anything.
- 04
The boiler starts up well but locks out after a few minutes of operation.
Cause: The flame maintenance solenoid valve gradually loses tightness as it heats up.
Note if the blockage always takes the same time to appear before considering the gas valve as the culprit.
Fault codes from Junkers that this part resolves.
| Code | Fault | Diagnosis and solution |
|---|---|---|
| FA | After the gas disconnection: The flame is still detected. | The gas valve does not close tightly (leak/blockage) and the control continues to read ionisation current even though the gas has been cut off. Verify with a leak test and observe that the ionisation signal disappears when closed, and that the solenoid valve closes correctly. |
| d7 | Fault in the regulating valve. | The electronics detect a fault in the gas valve (open/shorted coils or jammed mechanism). Check control voltage and coil continuity/ohmage, and ensure the valve opens/closes by measuring pressure on the ramp. |
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.
Data sheet for the gas valve Junkers 8747003700
- Catalogue reference
- 8747003700
- Brand
- Junkers
- Type of part
- Gas valves
- Units in stock
- 5 units
- Status
- Refurbished
- Warranty
- 1 year
- Shipping
- 1-2 business days
- Return
- 14 days
Data read on the part and in the manufacturer's documentation
What we have not been able to verify does not appear here.
- model
- 845 SIGMA
- Manufacturing origin
- Made in Italy (Padua)
- CE Certificate
- 0063AS4831
- Cross code
- 8 747 003 700
- gas
- ALLGAS
- Maximum inlet pressure
- Pi max 60 mbar
- Output pressure
- Po 1-36 mbar
- ev1
- 24V RAC, 6.5 VA class B
- ev2
- 24V RAC, 2.8 VA class J
- modulator
- MD MAX 17V DC
- Maximum current
- MAX 165 mA
- Ambient temperature
- 15/60°C
- code (production)
- 0845105
- date (production)
- 0949
- lot
- 2934903
- nr
- 2271
Frequently asked questions about the gas valve 8747003700
Does this gas valve Ref. 8747003700 work for a boiler ZWC 35/35-3 MFA?
Does the same valve work for a boiler ZWN 24-7 AE?
When should this valve be replaced in a ZWC or ZWN boiler?
How many solenoid valves does the valve of the ZWC/ZWN series have?
What is the reference for this gas valve?
How many models are compatible with this gas valve?
Spare parts related to Junkers Ceraclass Excellence / Comfort (ZWC)
