Common problems guide

The most common Baxi Duo-tec 2 Combi 28 Compact problems

The faults most likely to send a Baxi Duo-tec 2 Combi 28 Compact 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.
17 documented codes
6 most common
0 DIY-safe checks
6 engineer needed

The 6 most common faults

01
118 Engineer

As pressure reduces Error Code 118 will begin to flash. Once the pressure is less than 0.5 bar the boiler will not operate & 118 will be displayed constantly

Full guide for 118

Call a Gas Safe engineer if…

  • You can smell gas or see signs of a leak
  • The Baxi 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 17-code list for the Baxi Duo-tec 2 Combi 28 Compact

Related guides

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