Junkers Eurostar Air Pressure Switch ACU HIT Zwse 28 4 MFA Ref. 8716761918
The air pressure switch checks the pressure in the boiler and allows it to operate. This Junkers model, with reference 8716761918, is essential for the boiler to start correctly. When it fails, the boiler may not start or may lock out even if the pressure is adequate, which can manifest with fault codes C1, C4, or C6. It is compatible with Junkers Eurostar ACU HIT boilers, such as the models ZWSE 28-4 MFA and ZWSE 28-5 MFA, among others. A technician should confirm through diagnosis whether it needs to be replaced if you experience these symptoms to avoid issues with your boiler's operation.
- Type of part
- Pressure switches
- Status
- Refurbished
- Catalogue reference
- 8716761918
- Warranty
- 1 year
Junkers boilers compatible with reference 8716761918
Pressure switch with reference 8716761918. Two confirmed compatibilities: ZWSE 28-4 MFA and ZWSE 28-5 MFA.
Proven compatibility
| Boiler model | Family | Verification |
|---|---|---|
| Junkers ZWSE 28-4 MFA | Junkers Eurostar ACU HIT | Contrasted |
| Junkers ZWSE 28-5 MFA | Junkers Eurostar ACU HIT | 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. 8716761918 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 8716761918. 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 pressure switch 8716761918
The pressure switch controls the air or water pressure to authorize operation. These are the typical symptoms and what to do:
Common symptoms and faults
- 01
The boiler does not ignite and locks out indicating a fault with the pressure switch.
Cause: The pressure switch does not close the contact that confirms the extractor is generating enough pressure to ignite safely.
Check that the extractor starts, sounds normal, and does not take too long to gain speed before changing the pressure switch.
- 02
The extractor works normally, you can hear it, but the burner never starts.
Cause: Even though there is air pressure, the pressure switch does not transmit the closed contact signal to the control board.
With the boiler running, check if the pressure switch makes a noticeable click when the fan reaches speed; if it doesn't, the fault is likely in the component itself.
- 03
The fault mainly occurs during cold starts, and sometimes it resolves itself on the second or third attempt.
Cause: A contact that begins to degrade may fail intermittently, especially in cold conditions, before completely stopping to respond.
Note whether the fault occurs consistently or only sometimes, and under what conditions, to confirm that the pattern fits a faulty pressure switch.
- 04
The boiler locks out even though the flue is clean and clear on the outside.
Cause: If an external obstruction is ruled out, the fault lies in the pressure switch not validating the pressure even though it is correct.
Also check the internal silicone tubes of the pressure switch, because an internal blockage gives the same symptom as a faulty part.
Junkers fault codes that require diagnosis
| Code | Fault | Technical checks |
|---|---|---|
| C1 | The pressure switch opens during operation, or the fan speed is too low. | If the air pressure switch opens during operation due to a faulty diaphragm/contact or loss of pressure at its connections, the control board detects a lack of air flow. Check continuity at the pressure switch terminals with the fan running and inspect/clean silicone tubes and venturi; if it does not switch within its threshold, replace it. |
| C4 | The pressure switch contact does not open. | With the fan stopped, the pressure switch should open; if it remains stuck/closed (contact or membrane seized), the boiler locks out. Check that the contact switches to open with the fan stopped and that there are no obstructions in the tubes; if it persists, replace the pressure switch. |
| C6 | The contact of the pressure switch box does not close. | When starting up, the fan must generate the vacuum for the pressure switch to close; if the pressure switch fails (membrane or microswitch) or does not reach the threshold due to dirt in inlets/tubes, it does not close and C6 appears. Verify the electrical closure of the pressure switch with the fan running and check/clean tubes and inlets; if it does not switch, replace it. |
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.
Datasheet for Junkers pressure switch 8716761918
- Catalogue reference
- 8716761918
- Uniclima internal SKU
- PCEZWSE284
- Brand
- Junkers
- Type of part
- Pressure switches
- 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.
- Part code
- 605.99621
- Switching pressure
- 51/43 Pa
- Contacts
- 0.2(0.1) A / 30V~
- Batch code
- KGFBBE
- Reference printed on the label
- 8716761918/2
- Brand printed on the label
- ELM LEBLANC
Manuals and technical documentation
Official documentation of the boiler, useful for locating the part and cross-referencing the fault codes.
- Junkers ZWSE 28-5 MFA manual (PDF) Document © Junkers, provided as a technical reference.
Frequently asked questions about the pressure switch 8716761918
Is this pressure switch suitable for the Zwse 28-5 MFA?
What fault does the air pressure switch of the Zwse 28-4 MFA 23 detect?
At what pressure does the pressure switch of the Junkers Zwse 28-4 MFA switch?
Does the reference 8716761918 match the label of this part?
