Skip to main content
F15 FAULT CODE
Glow-worm

eBUS Voltage Fault (Older Ranges)

Medium Severity Engineer Required

On Glow-worm Flexicom and Ultracom models, F15 indicates an eBUS voltage failure.

Step-by-Step Fix Guide

  1. Step 1

    Check wiring between the boiler and any connected controls

  2. Step 2

    Turn off at mains for 10 minutes

  3. Step 3 Engineer only

    If fault persists, call a Gas Safe engineer

Gas Safe Reminder

Work on gas appliances must be carried out by a Gas Safe registered engineer. The steps above cover safe checks a homeowner can perform - any internal component replacement requires a qualified professional. If in doubt, always call an engineer.

Are you a Gas Safe Engineer?

Access technical fault data, wiring diagrams, and parts lists. Free for verified Gas Safe engineers.