How much does it cost to fix Johnson Starley error code ER 12 + SPANNER?

Typical repair cost for the Johnson Starley ER 12 + SPANNER fault is £90-180 including labour.

ER 12 + SPANNER High

Johnson Starley ER 12 + SPANNER Fault Code

Q: What does the Johnson Starley ER 12 + SPANNER fault code mean?

Your boiler's internal sensor has detected an unusual temperature reading on the pipe returning from your radiators, suggesting a sensor fault or water flow issue.

Also written as ER12SPANNER — same fault.

The Johnson Starley ER 12 + SPANNER fault code means: your boiler's internal sensor has detected an unusual temperature reading on the pipe returning from your radiators, suggesting a sensor fault or water flow issue.. It appears on 1 Johnson Starley model in our database.

Technical description: CH return temp sensor out of range

Typical repair cost £90-180 (including labour)

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 →

Johnson Starley models that show the ER 12 + SPANNER fault code

Click a model for the full fault code list and model-specific repair notes.

Warmcair DW Repair: £90-180

Source

Johnson Starley ER 12 + SPANNER fault code information on this page is sourced and cross-checked against the official Johnson Starley service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026