BoilerFaultCodesWorcester Bosch EH 258 Fault Code
Also written as EH258 — same fault.
The Worcester Bosch EH 258 fault code means: your boiler’s internal computer has developed a serious communication fault or hardware failure, meaning it can no longer control the heating process safely.. It appears on 4 Worcester Bosch models in our database.
Technical description: Control box or the heat control module (HCM) is defective – HCM or control box connections need to be checked
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 EH 258: 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 EH 258 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Worcester Bosch EH 258 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