Worcester Bosch A8 361 Fault Code
Also written as A8361 — same fault.
The Worcester Bosch A8 361 fault code means: your boiler's internal computer is having a communication error and cannot recognise its own control settings, meaning it will not operate.. It appears on 2 Worcester Bosch models in our database.
Technical description: HCM invalid
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
Gas Safe Register →Avoid the next call-out bill
A cover plan would handle faults like A8 361: no call-out fees, no surprise bills.
Affiliate links. We may earn a commission at no extra cost to you.
Worcester Bosch models that show the A8 361 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Worcester Bosch A8 361 fault code information on this page is sourced and cross-checked against the official Worcester Bosch service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026