Common problems guide

The most common Saunier Duval Semia Condens F30 E problems

The faults most likely to send a Saunier Duval Semia Condens F30 E into lockout — with plain-English causes, what to check first, estimated repair costs and whether you need a Gas Safe engineer.

This model is discontinued. Parts can be harder to source and expensive. If repair costs are mounting, a new A-rated boiler may be the smarter choice.
4 documented codes
4 most common
0 DIY-safe checks
4 engineer needed

The 4 most common faults

02
01 Engineer

Ignition problems / Air-gas mix ratio is incorrect preventing combustion and forcing the boiler into a state of lockout.

Full guide for 01
03
05 Engineer

The boiler is overheating and the Safety Thermostat has triggered / The boiler flue is overheating and the Flue Safety Thermostat has triggered.

Full guide for 05

Call a Gas Safe engineer if…

  • You can smell gas or see signs of a leak
  • The Saunier Duval shows an Emergency or High severity code
  • The boiler keeps locking out after repeated resets
  • You've tried the DIY checks and the fault hasn't cleared
  • There's visible water leaking from the boiler
  • The flame is yellow or orange instead of blue
See the full 4-code list for the Saunier Duval Semia Condens F30 E

Related guides

Boiler losing pressure → No hot water → When to replace → Symptom checker →