Need to Replace a Part?
If your Ferroli boiler is showing high water pressure, it may be due to a faulty part. At Suner, you can find original Ferroli spare parts ready to ship. We stock expansion vessels, pressure relief valves, safety valves, pressure sensors, and more—everything you need to keep your boiler running safely and efficiently.
Why It’s Important to Control Boiler Pressure
High water pressure in a Ferroli boiler is usually caused by a small fault, such as a stuck filling valve, or a natural increase in pressure when heating is active. But sometimes it’s a sign of more serious issues that require attention.
Common Error Codes Related to High Pressure in Ferroli Boilers
In models like the Bluehelix Maxima, the following alerts may appear:
A26 Error
Indicates that the water pressure has exceeded the limit three times within one hour.
- Possible cause: The pressure is too high. The expansion vessel may be discharged or damaged.
- Solution: Drain some water from the heating circuit to relieve pressure. Check the expansion vessel and recharge or replace it if necessary.
F21 or F40 Error
Signals abnormally high pressure in the system.
- Possible causes: The filling valve is stuck open or the expansion vessel is not functioning.
- Solution: Partially drain the system. Inspect the filling valve and pressure control system. Check the expansion vessel and replace it if needed.
Symptoms and Fixes for High Water Pressure
Even without error codes, high water pressure can create issues. Here are common situations and how to fix them:
| Symptom | Cause | Solution |
| Pressure rises above 2 bar, even when the boiler is off | The filling valve was left open or is stuck | Close the valve. If it’s stuck, lubricate or replace it |
| Pressure increases too much when heating is on | There’s air in the heating system | Bleed radiators and the boiler, and check for leaks |
| Pressure gauge shows over 2.5 bar | Normal pressure rise during operation | Release water from a radiator or the drain valve |
| Pressure keeps rising and the safety valve opens | Expansion vessel has lost gas or is damaged | Recharge the gas chamber, repair or replace the vessel |
| Water leaking from the safety valve | Safety valve is worn out | Replace it with one rated at 3 bar |
About the Ferroli Bluehelix Maxima Boiler
This is a high-efficiency, wall-mounted gas boiler with a stainless steel heat exchanger and low-emission design. It includes a microprocessor that manages temperature and combustion, and it supports installation indoors or outdoors (with freeze protection if needed).
It’s recommended to check the system pressure at least twice a year during active use.
Conclusion
If your Ferroli boiler is showing high water pressure, it may be a simple fix like closing a valve or bleeding the radiators. But if the issue keeps returning, it could be due to a damaged expansion vessel, stuck filling valve, or faulty safety valve. Regular maintenance and timely replacement of parts will keep your boiler safe and running efficiently.
Remember, if you need replacement parts, you can find original Ferroli components quickly and easily at Suner.