Common problems guide

The most common Biasi Garda M90f problems

The faults most likely to send a Biasi Garda M90f into lockout — with plain-English causes, what to check first, estimated repair costs and whether you need a Gas Safe engineer.

This model is discontinued. Parts can be harder to source and expensive. If repair costs are mounting, a new A-rated boiler may be the smarter choice.
3 documented codes
3 most common
2 DIY-safe checks
1 engineer needed

The 3 most common faults

01
lock-out light High DIY-safe

Your boiler has shut down for safety because it either failed to light, sensed it was getting too hot, or detected an issue with how it clears waste gases.

What to try first

Check that your gas pre-payment meter (if applicable) has credit.Ensure any external gas isolation valves are fully open.Press and release the reset button on the front control panel to see if the boiler restarts.

Est. cost
£100-350
Parts
Ignition Electrode, Safety Thermostat, Air Pressure Switch
Full guide for lock-out light
02
All Lamps OFF High DIY-safe

Your boiler appears to have no electrical power at all, meaning the screen and lights are completely blank.

What to try first

Check if the boiler's power switch is turned onCheck your home's main fuse box (consumer unit) for a tripped circuit breakerCheck the fuse in the spurred power socket next to the boiler

Est. cost
£120-350
Parts
Electronic Control PCB, Internal Fuse, Mains Cable
Full guide for All Lamps OFF
03
All Lamps ON High Engineer

Your boiler's internal computer has suffered a critical failure and can no longer control the heating or hot water functions.

Est. cost
£250-£400
Parts
Main Printed Circuit Board (PCB)
Full guide for All Lamps ON
Parts most often replaced

on the Biasi Garda M90f

Ignition ElectrodeSafety ThermostatAir Pressure SwitchGas ValveElectronic Control PCBInternal Fuse

Based on parts cited in our fault code database. Your engineer will confirm what's actually needed after diagnosis.

Call a Gas Safe engineer if…

  • You can smell gas or see signs of a leak
  • The Biasi shows an Emergency or High severity code
  • The boiler keeps locking out after repeated resets
  • You've tried the DIY checks and the fault hasn't cleared
  • There's visible water leaking from the boiler
  • The flame is yellow or orange instead of blue
See the full 3-code list for the Biasi Garda M90f

Related guides

Boiler losing pressure → No hot water → When to replace → Symptom checker →