BoilerFaultCodesWhat the manual says
Manufacturer manualNO CONNECTION TO PRIMARY PCB
Shared across the Logic Max HEAT2 range
This code is shared by the boilers in this range, which use the same control board. It may not be printed in this exact variant’s manual.
What causes this fault?
This fault occurs when the electrical connection between the boiler's internal computer and the front screen is broken or lost. The most common reason is a failure of the display circuit board itself, or a blown fuse on the main control board caused by an internal electrical surge.
Engineer required
This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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All 84 fault codes on the Logic Max Heat 2
Seeing a different code? Every code this model can display, in one place.
4.24.34.44.54.64.74.84.94.104.114.124.144.154.16059.1.59.1.8121314151617181924252829303132363738435460657071758283113115116Blocked Flue/CondensateE4EAEdF9Fan FaultFdFlame LossFlame On Before Gas OnFlame on before gas valve onFlow Thermistor FaultFlow/Return ReversedFUSEGas Valve FaultH nH0Ignition LockoutL AL EL1LCDLow Mains VoltageNO CH OPERATIONNo Water FlowOutside Sensor FaultOverheat LockoutP1P4PCB FaultReturn ThermistorReturn Thermistor FaultRoom Thermostat FaultService DueService RequiredSpare PCB Not SetToo Many Restarts