Ferroli · Optimax 25 S
F3 boiler fault code
Optimax 25 S
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Renting? Report it to your landlord or housing provider first. They are responsible for gas safety and boiler repairs, and the repair should not cost you.
What F3 means
The manual groups F1 with F3 and F8: no communication between the electronic unit and gas valve.
Safe check
Record the code and model from the outside label. Do not open the boiler, touch wiring, or check gas-control parts.
When to contact an engineer
This code is associated with an internal gas-control communication fault; arrange diagnosis by a Gas Safe registered engineer.
Safety notice
A boiler fault code alone is not a gas or carbon-monoxide emergency. If you smell gas, a CO alarm sounds, anyone feels unwell, or there is an unsafe flame, leave and call 0800 111 999 from outside.
Source and provenance
- Optimax 25 S · reference 35446965 · code 3544696/5 · troubleshooting table, printed p. 26
instructions for use, installation and maintenance
05/2005 · code 3544696/5