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BoilerCodes
F.84
Glow-worm fault code

Glow-worm F.84: what it means on your model

Engineer only

F.84 means different things on different Glow-worm models. Check the table below against your boiler's model name, which is usually on the front panel or in your user manual.

What you can safely do

There is nothing you can safely do yourself with this one. Leave the boiler off and book an engineer.

Call a Gas Safe engineer if

  • Book a Gas Safe registered engineer.
Find a Gas Safe engineer near you Opens the official Gas Safe Register search.

Applies to: Energy range, Betacom A range. Codes can differ between models, so check your manual.

What F.84 means on each Glow-worm model

From Glow-worm's own fault tables. Your model name is usually on the front of the boiler or in the user manual.

ModelMeaningCauses listed for engineers
Energy rangeFlow/return temperature sensor faultInconsistent readings, sensors swapped or incorrectly installed
Betacom A rangePermanent temperature difference between flow and return heating sensorsNot listed

Common questions about Glow-worm F.84

Can I fix Glow-worm F.84 myself?

No. It needs a Gas Safe registered engineer to diagnose. Tell them the exact code and your boiler's model name.

Nearby Glow-worm codes

F.71F.73F.74F.76F.77F.83F.85F.86F.87F.89

See all 41 Glow-worm codes

Sources