d.88 Medium

Boiler Fault Code d.88

Also written as D88 — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed

Fault code d.88 appears across 2 boiler brands and 15 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler is struggling to detect the flow of water needed to switch on your hot water tap, meaning it cannot ignite to heat the water for your shower or taps. (As reported on Glow-worm MicraCom)

Pick your boiler brand for the d.88 fix

Glow-worm d.88 7 models Vaillant d.88 8 models

Source

Information for the d.88 fault code is sourced from the official service / installation manual for each model that displays it. Read more about how we source fault codes →

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026