Low
LED 3 on Ferroli Modena F

Your boiler is currently working to heat your tap water, which is a normal operating status rather than a fault.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Monitor it

This is a minor fault. Keep an eye on it and mention it at your next annual boiler service. Reset the boiler and see if it clears.

Technical description

Domestic Hot Water circuit ON

DIY fix possible

Check if a hot water tap is currently turned on or drippingEnsure your pre-heat function is not active if the light stays on while taps are closedMonitor the boiler to see if the light goes off once the water reaches temperature

Find a Gas Safe engineer
Search the official register →

Related fault codes

LED 1View →LED 2View →

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 →