Common problems guide

The most common Baxi Ecoblue Advance Combi problems

The faults most likely to send a Baxi Ecoblue Advance Combi 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
3 DIY-safe checks
3 engineer needed

The 6 most common faults

01
E118 High DIY-safe

Your boiler has stopped working because the amount of water inside the system has dropped too low.

What to try first

Locate the external filling loop, usually two taps connected by a small flexible silver hose underneath the boiler.Open the taps slowly to let more water into the system until the pressure gauge reads between 1.0 and 1.5 bar.Close both taps tightly and ensure the boiler resets itself or restart it.

Est. cost
£0-£120
Parts
Filling loop, Pressure relief valve, Expansion vessel
Full guide for E118
02
117 High DIY-safe

Your boiler has detected that the water pressure inside your heating system is currently too high for it to operate safely.

What to try first

Locate a radiator in your home with a bleed valve.Place a cloth or small container under the valve.Slowly open the valve to let a small amount of water out until the pressure gauge on the front of the boiler drops into the green zone (usually 1.0 to 1.5 bar).

Est. cost
£80-150
Parts
Pressure Relief Valve (PRV), Expansion Vessel, Filling Loop
Full guide for 117
03
118 High DIY-safe

Your boiler has stopped heating and providing hot water because the water pressure inside the system has dropped below the necessary level.

What to try first

Locate the filling loop, which is a silver braided hose with one or two valves underneath your boiler.Open the valves slowly to allow water into the system until the pressure gauge on the front of the boiler reads between 1.0 and 1.5 bar.Close the valves tightly to ensure no water continues to leak into the system.

Est. cost
£0-90
Parts
Filling loop, Pressure relief valve, Pressure sensor
Full guide for 118
04
133 High Engineer

Your boiler has stopped working because it failed to light or stay lit, meaning you currently have no heating or hot water.

Est. cost
£120-250
Parts
Ignition lead, Ignition electrode, Gas valve
Full guide for 133
05
20 High Engineer

Your boiler has lost the ability to accurately measure the temperature of the water circulating through your radiators, so it has shut down to prevent overheating.

Est. cost
£120-200
Parts
Central heating NTC temperature sensor, Wiring harness
Full guide for 20
06
28 High Engineer

Your boiler has detected an issue with the sensor that monitors the temperature of the exhaust gases exiting the flue.

Est. cost
£150-250
Parts
Flue Gas Sensor, Wiring Harness
Full guide for 28
Parts most often replaced

on the Baxi Ecoblue Advance Combi

Filling loopPressure relief valveExpansion vesselPressure Relief Valve (PRV)Expansion VesselFilling Loop

Based on parts cited in our fault code database. Your engineer will confirm what's actually needed after diagnosis.

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 Ecoblue Advance Combi

Related guides

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