Baxi E118 Fault Code

The Baxi E118 fault code means the primary system water pressure is too low.

Symptoms of the E118 error include cold radiators, little to no hot water, and in severe cases complete boiler shutdown.

Low boiler pressure, usually below 0.5 bars, indicates a system leak or other internal malfunction, such as a pressure valve issue.

To fix the E118 fault, the central heating system needs to be repressurised. This is done via the filling loop and is an easy DIY fix.

This is your troubleshooting guide on how to restore boiler pressure and eliminate E118 error codes from your boiler system.

In the case of persistent fault codes, chat with our expert team.

Here at ADI Leak Detection we specialise in finding and repairing hidden water leaks on central heating systems – resolving the E118 error.

E118 Error Code

Symptoms Of The E118 Fault Code

Symptoms of the E118 error code include:

  • The boiler error code E118 displayed on the panel screen
  • Cold radiators
  • Little to no hot water
  • Pressure gauge below 1 bar
  • Boiler not igniting
  • Temperature fault/fluctuations
  • Boiler not working (complete system shutdown)
  • A low system warning light (if your boiler has one)

Let’s see how you can fix this fault code next.

How To Fix The E118 Fault

You can clear the E118 fault on your boiler by pressurising the central heating system.

Step 1

  • Check the water pressure on the pressure gauge.
  • Refer to your boiler manual for its precise location.
  • The ideal system pressure for a Baxi boiler is between 1 – 2 bars.

Step 2

  • If the pressure is below 1 bar you need to top up the pressure via the filling loop. The filling loop has two brass levers and is found underneath the boiler or close to a sink.
  • Turn the lever to allow water to flow into the system from the main supply line.
  • Close the lever once the boiler has reached the optimum pressure range.

Step 3

  • Check the boiler for leaks.
  • Inspect radiators, pipework, and valves for signs of dripping water.
  • Replace or repair damaged or leaky components if necessary.

Step 4

  • Reset the boiler by turning it off for a few minutes.
  • This will clear the E118 error code if it’s a temporary error.

Other tips

  • If E118 boiler errors reappear, you either have a system leak or a faulty pressure valve on your hands. If you suspect a leak but can’t locate it, you’ll need to contact leak detectors.
    Professionals use non-invasive methods, such as tracer gas and thermal cameras, to locate hidden leaks.
  • If the pressure valve is faulty, contact a professional Gas Safe engineer.

What Should I Do If The E118 Error Keeps Displaying

If the E118 fault code comes back after repressurising the boiler you should contact a leak detection expert. These professionals are equipped to pinpoint the leak source using non-destructive techniques. Methods include borescope cameras, damp meters, and acoustic devices.

If E118 error persists:

  • Safety first – ensure the boiler is turned off and cooled down before attempting any DIY fixes.
  • Recheck for leaks by thoroughly inspecting all radiators, valves, etc. Pay close attention to joints and connections and look for signs of dripping water.
  • Ensure pressure stability on the pressure gauge. Pressure should remain within the range of 1 to 2 bars. Recheck the pressure readings after topping up the boiler. Refer to the boiler manual when in doubt.
    Low readings indicate lost pressure, a potential pressure sensor error, or a leak within the system. Seek professional assistance for full diagnosis and repair.

Contact ADI for a professional leak detection services on 0800 731 3843 to detect and repair your central heating the leak.

Adrian Morgan

Adrian Morgan CIPHE RP RHP is the founder & Managing Director of ADI Pro Leak Ltd. Adrian is also the Head Plumbing, Heating & Leak Detection engineer at ADI Leak Detection.

Adrian CIPHE RP RHP is proud to be registered with the Chartered Institute of Plumbing & Heating Engineering, a Registered Plumber and a Registered Heating Professional.