Unknown
Neon 2 not lit on Glow-worm Micron 100FF

Glow-worm Micron 100FF fault code Neon 2 not lit

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

What the manual says

Manufacturer manual

Low water pressure (sealed system), Overheat cut off device tripped or thermostat, overheat cut off device faulty

From this model's manual
Verified against the Glow Worm/Glow Worm Micron 100ff installation & service manual.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

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 →
Boiler cover options

Avoid the next call-out bill

A cover plan would handle faults like Neon 2 not lit: no call-out fees, no surprise bills.

Approved partner
Domestic Appliance Guard
Unlimited call-outs, 24/7 helpline, no price-hike promise
Get a quote →

Affiliate links. We may earn a commission at no extra cost to you.

All 5 fault codes on the Micron 100FF

Seeing a different code? Every code this model can display, in one place.

Main burner not operatingNeon 1 not litNeon 3 not litNeon 4 not lit

Related guides you might find useful

Is boiler cover worth it?

Break-even maths on monthly cover.

Read →

When to replace your boiler

7 signs repair isn't worth it anymore.

Read →

New boiler cost 2026

Realistic UK prices for a swap.

Read →