Glow-worm Flexicom Fault Codes
The Glow-worm Flexicom was the brand's mainstream range of the late 2000s and early 2010s — the Flexicom cx combi, sx system and hx heat-only — and plenty remain in service. It reports faults as F-codes on its digital display, covering the usual condensing-boiler territory: ignition failure, flame loss, overheat, sensor faults, fan and flue problems, and pressure. Flexicoms are now senior boilers, and their fault statistics look like it: wear in ignition components, pumps, fans and sensors dominates, with the aluminium heat exchanger rewarding whatever water treatment it received over the years. Parts availability is still reasonable. The codes below link through to full diagnosis pages — and as with any range of this age, your specific model year's manual is the final word where generations differ.
Where Flexicom fault codes appear
The Flexicom has a digital display showing an F-prefixed code when a fault trips. Some faults show briefly before lockout, so if the boiler is cycling and failing, watch the display through an attempt — the code that appears at the moment of failure is the diagnostic one.
Resetting a Glow-worm Flexicom
Press the reset button briefly; the boiler clears and retries. Pressure-related codes want a top-up to 1–1.5 bar via the filling loop first. Recurring codes on a boiler this age are wear talking — book a Gas Safe engineer, and weigh repair costs against age honestly once they mount.
Common Flexicom problems
Late-life Flexicoms mostly log ignition lockouts (electrodes, leads, gas valves — plus winter condensate freezes), overheat and circulation codes as pumps tire and systems sludge, and the sensor failures of age. A magnetic filter fitted even now pays for itself on these systems; much of what ends a Flexicom is sludge-driven and preventable.
Most common Flexicom fault codes
- F1 The F1 code appears on Glow Worm boilers when the boiler has attempted to light itself… Read more →
- F4 The F4 code means your Glow-Worm boiler has failed to detect a flame during the ignition… Read more →
- F5 The F5 code means your Glow-Worm boiler has detected that internal temperatures have… Read more →
- F9 The F9 fault code on a Glow-Worm boiler indicates that the boiler's control board has… Read more →
- F13 The F13 code appears on Glow-Worm boilers when the main PCB detects a problem with its… Read more →
- F22 The F22 fault code on a Glow-Worm boiler signals that the water pressure inside your… Read more →