Common problems guide

The most common Chaffoteaux Minima MX2 24FF / 30FF problems

The faults most likely to send a Chaffoteaux Minima MX2 24FF / 30FF 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.
5 documented codes
5 most common
3 DIY-safe checks
2 engineer needed

The 5 most common faults

01
70 - 80 High DIY-safe

Your boiler has switched itself off because it has detected that the internal water temperature is getting too hot.

What to try first

Check that all radiator valves are fully open to allow water to circulate.Ensure the system pressure is between 1.0 and 1.5 bar on the pressure gauge.Press the 'Reset' button to see if the fault clears.

Est. cost
£120-350
Parts
Circulation Pump, Overheat Thermostat, Heat Exchanger
Full guide for 70 - 80
02
60 - 70 - 80 High DIY-safe

Your boiler is failing to light the gas even though it is trying to, which means it cannot provide any heating or hot water for your home.

What to try first

Check if other gas appliances in your home, like a hob, are working to ensure you have a gas supply.If you have a prepayment meter, check that you have enough credit.Press the 'Reset' button on the front control panel to see if the boiler restarts.

Est. cost
£120-280
Parts
Ignition electrode, Flame sensing electrode, Gas valve
Full guide for 60 - 70 - 80
03
30 High DIY-safe

Your boiler has stopped working because water is not moving around the internal system efficiently enough to prevent it from overheating.

What to try first

Check that the boiler pressure is between 1.0 and 1.5 bar on the gaugeEnsure all radiator valves are fully openCheck if the pump is making any unusual grinding or humming noisesTry restarting the boiler using the reset button

Est. cost
£150-£350
Parts
Central heating pump, Main heat exchanger, Flow thermistor (NTC sensor)
Full guide for 30
04
30 - 40 High Engineer

Your boiler has detected a faulty internal temperature sensor that monitors the water returning from your radiators, which prevents the system from heating effectively.

Est. cost
£90-160
Parts
Central heating return thermistor (NTC sensor), Wiring loom connector
Full guide for 30 - 40
05
30 - 40 - 50 - 60 - 70 - 80 Emergency Engineer

Your boiler has detected that it is getting dangerously hot and has shut itself down to prevent damage or fire risk.

Est. cost
£120-250
Parts
Overheat thermostat, Central heating pump, Diverter valve
Full guide for 30 - 40 - 50 - 60 - 70 - 80

on the Chaffoteaux Minima MX2 24FF / 30FF

Circulation PumpOverheat ThermostatHeat ExchangerIgnition electrodeFlame sensing electrodeGas valve

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 Chaffoteaux 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 5-code list for the Chaffoteaux Minima MX2 24FF / 30FF