BoilerFaultCodesWhat the manual says
Manufacturer manualMain PCB / Display PCB fault
From this model's manual
Verified against the Glow Worm/Glow Worm Ultracom 35 Store 4701915 installation & service manual.
What causes this fault?
This fault occurs when the main control board and the display panel lose their ability to communicate with each other. It is usually caused by a physical failure of the electronic components or a loose connection in the internal wiring, preventing the boiler from confirming it is safe to ignite.
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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Related fault codes
All 70 fault codes on the Ultracom 35 Store
Seeing a different code? Every code this model can display, in one place.