BoilerFaultCodesTechnical description
Frost protection occurs; outdoor unit will stop operating.
What causes this fault?
This code appears when the outside temperature drops low enough that the unit needs to protect its internal pipework and heat exchanger from freezing. It occurs because the system has detected a risk of ice buildup and has paused normal heating to circulate water or activate internal heaters. This is a built-in safety feature designed to prevent permanent damage to the outdoor unit during cold snaps.
This code is strictly seasonal and will only appear during the winter months when outdoor temperatures approach or fall below freezing.
DIY fix possible
Check that the outdoor unit is clear of snow, ice, or leaf debrisEnsure the airflow around the outdoor unit is not obstructedWait for the unit to complete its automatic defrost or warming cycle