
Filling Key for Boiler FE-20E - Ref. 77823800
If you notice that you cannot fill the heating circuit or that there is a water leak causing a pressure increase, you may need the filling key for the boiler FE-20E. This part allows you to replenish water to the heating circuit, ensuring that it maintains the proper pressure. It is installed in models such as the Ecocompact FE 20-E and Ecocompact FE 20E/2 N, among others. If you observe these symptoms, it is time to replace the filling key.
VAT included
Consult via WhatsAppFagor boilers compatible with reference 77823800
Filling key with reference 77823800. Three confirmed compatibilities: Ecocompact FE 20-E and Ecocompact FE 20E/2 N.
Proven compatibility
| Boiler model | Family | Verification |
|---|---|---|
| Fagor Ecocompact FE 20-E | Fagor | Contrasted |
| Fagor Ecocompact FE 20E/2 N | Fagor | Contrasted |
| Fagor Ecocompact FE 20E 1N | Fagor | 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. 77823800 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 77823800. 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 and faults that the filling valve 77823800 resolves.
The filling valve allows water to refill the heating circuit. These are the typical symptoms and what to do:
Common symptoms and faults
- 01
You need to frequently top up the installation, even if you don't see any leaks.
Cause: The valve does not close properly and allows water to pass through slowly.
Close the valve properly and monitor the pressure gauge for a couple of hours to see if the pressure continues to drop.
- 02
There is moisture around the red control knob of the valve.
Cause: The o-ring or the stem seal has worn out over time.
Dry the area and tighten the pressure switch of the control before replacing the complete valve.
- 03
Do you have difficulty turning the knob or does it get stuck when trying to refill?
Cause: Limescale builds up in the internal mechanism and hinders rotation.
Move the control gently and check if the water in the area is very hard before forcing 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.
Fiche of the filling key Fagor 77823800
- Catalogue reference
- 77823800
- Brand
- Fagor
- Type of part
- Filling valves
- Units in stock
- 1 unit
- Status
- Refurbished
- Warranty
- 1 year
- Shipping
- 1-2 business days
- Return
- 14 days












