Error F37 on Ferroli Boilers: How to Refill Water Pressure in 1 Minute
If your Ferroli gas boiler (such as Bluehelix Tech, Domiproject, Divatech, or Silent D) is flashing error code F37, do not panic. It simply indicates that internal water pressure in the heating circuit has dropped below 0.8 bar. The boiler enters protective lockout to prevent dry firing of the primary heat exchanger.
How to Resolve Error F37 in 3 Simple Steps
1. Locate the filling valve: Beneath the boiler, find the small plastic knob or lever (usually colored blue or black).
2. Turn the knob counterclockwise: You will hear the sound of water entering the heating circuit.
3. Monitor the front digital display or analog pressure dial: Stop when the pressure reads between 1.2 and 1.5 bar by closing the valve firmly clockwise.
As soon as adequate pressure is registered by the electronic pressure sensor, error code F37 will clear automatically within seconds.
Why Does Error F37 Keep Happening?
If your Ferroli boiler drops pressure every few days, common causes include:
1. Defective Digital Pressure Sensor: Scale or sludge obstructing the sensor aperture.
2. Ruptured Expansion Vessel Membrane: Thermal pressure surges releasing water out the 3-bar drain.
3. Minor Seepages in Underfloor Heating or Radiators: Weeping fittings in the distribution network.
FAQ
What should I do if turning the blue knob does not increase pressure?
The mains water supply stopcock may be closed, or the filling valve spindle has stripped internally and needs replacement.
What is the correct pressure for a Ferroli boiler?
The optimal pressure in cold standby is 1.2 to 1.5 bar.