BoilerFaultCodesTechnical description
No valid DSN in display and/or main board. Spare part failure display and main board interchanged at same time and device specific number not adjusted
What causes this fault?
This fault occurs when the boiler's internal computer experiences a data mismatch or memory loss regarding its own model settings. The most common reason is that a replacement part was installed without being programmed correctly, or a power surge has corrupted the software communication between the main control board and the display unit.
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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