H9 / L9 / HA Display
All these codes relate to overheating, and can be treated the same.
Is the reading on the system pressure gauge above 0.5bar?
This fault can occur if all radiators are fitted with TRV'S
Does the system contain a lot of air - this can generally be heard in the radiators, if so bleed radiators
If the pressure is normal attempt reset.
- If the display changes to
, wait approx 30 mins to allow the boiler to cool, then try to reset again. During this period the fan will continue to run. ensure system pressure is above 1 bar and all TRV's are open during this period -
If the fault code remains : Engineer visit required