Baxi boiler error codes

When your Baxi boiler flashes an error code, it can be worrying, especially during a cold snap when you need heating and hot water the most. But don't stress: these codes are designed to help you (or an engineer) quickly identify what's gone wrong. From minor pressure drops to sensor faults, understanding what your boiler is telling you could save you time, money, and unnecessary disruption.

In this guide, we'll break down common Baxi boiler error codes, explain their meanings, and help you determine whether you can safely perform a simple check or if it's time to call in the professionals.

At Maintracts Services Ltd, we've been trusted by homeowners across London since 1974. Our Gas Safe-registered engineers have extensive experience in diagnosing and repairing Baxi boiler faults. From ignition issues to circulation problems, we're here to get your home warm and comfortable again, safely and efficiently.

Call us today on 020 8682 2244 to speak with our team about your Baxi boiler; we're ready to help, day or night.

 

 

Understanding Baxi Boiler Error Codes

Baxi boilers are built with smart technology to help keep your home warm, safe, and efficient. When something isn't quite right, they display an error code — the boiler's way of guiding you to the source of the problem. These codes can relate to simple fixes or signal deeper faults. Understanding what they mean helps you spot quick solutions and know when it's time to call professionals for expert help.

Let's examine the primary types of faults these codes represent and the reasons they appear.

Temporary vs Permanent Faults

• Temporary faults: Often caused by low pressure or a sensor malfunction. These may clear after a reset.
• Permanent faults: More serious issues that require professional attention to repair.

Water Pressure: A Common Cause

• Baxi boilers require a water pressure of between 1 and 3 bar.
• If pressure is too low, the boiler may shut down to protect itself.
• Topping up may help, but repeated low pressure means it's time to call an expert.

Sensors And Supply

Error codes can also mean:

• Water isn't circulating properly
• Temperatures are too high or too low
• There's a gas supply issue

These codes keep your home safe by spotting problems early.

Also Read: Glow-Worm Boiler Error Codes

 

Common Baxi Boiler Fault Types And Error Codes

When your Baxi boiler displays an error code, it indicates a specific type of fault. To help you understand the potential issue, here is a breakdown of the most common fault types and their related error codes.

1. Water Pressure and Circulation Faults

What it means

Your boiler needs the correct water pressure and good circulation to work efficiently and safely.

Typical signs

• Boiler fails to fire up
• Radiators stay cold
• Gurgling or banging noises

Common codes

• E118 / E119 / E125 / E270 (Baxi 600 / 800 / System / GA / EcoBlue) – Low system pressure, poor circulation, dry fire
• 1 red flash (Main Eco Compact / Heat) – Sensor or flow fault
• E2 / E109 (Avanta) – Poor or no circulation
• 117 / 119 (EcoBlue) – High or low system pressure

What you can try

• Check the pressure gauge (aim for 1–1.5 bar) and top up if needed
• Bleed radiators to remove air
• If pressure drops repeatedly or the issue continues, call Maintracts

2. Ignition, Flame and Gas Supply Faults

What it means

The boiler is struggling to ignite or maintain the flame.

Typical signs

• No heating or hot water
• The boiler makes repeated attempts to start

Common codes

• E133 / E128 / E4 / E384 / E135 (various models) – Ignition failure, flame loss, gas supply issue
• 3 red flashes (Main Eco Compact / Heat) – Ignition fault
• E133 (Duo-tec / Megaflo) – Ignition fault

What you can try

• Check that the gas supply is on (including prepayment meter credit)
• If the gas supply is fine but the code persists, call a gas safe engineer

3. Temperature, Overheating, and Flue Faults

What it means

The boiler is overheating or struggling to vent gases safely.

Typical signs

• Boiler locks out
• Unusual noises or smells

Common codes

• E110 / E130 / E131 / E164 (various models) – Overheat, flue overheat, fan or flue fault
• 2 red flashes (Main Eco Compact / Heat) – Over-temperature lockout
• E28 (various models) – Flue thermistor fault

What you can try

• Bleed radiators to improve flow
• Check that external flues or vents are not blocked
• If the fault persists, call Maintracts

4. Sensor, PCB and Internal Faults

What it means

There is a fault with internal sensors or communication between boiler parts.

Typical signs

• The boiler is unresponsive or displays fault codes
• Intermittent loss of heating or hot water

Common codes:

• E20 / E40 / E28 / E321 (various models) – Sensor faults
• E167 / E83 / E384 (various models) – PCB or internal communication faults
• 4 / 5 / 6 red flashes (Main Eco Compact / Heat) – Fan, parameter or wiring faults

What you can try:

• These faults will require a professional diagnosis — contact Maintracts

Also Read: Ideal Logic Boiler Fault Codes

How to Reset a Baxi Boiler

If your Baxi boiler shows an error code, resetting it may clear temporary faults. Here's how:

1. Find the reset button: Usually marked with a flame symbol or "reset."
2. Press and hold: Hold for 5–10 seconds.
3. Wait: The boiler should attempt to restart.

When To Reset

• After topping up low-pressure
• After confirming that the gas supply is OK
• After checking external vents/flues

When Not to Keep Resetting

• If the same error keeps returning
• If you smell gas
• If the boiler locks out repeatedly

Repeated resets can cause more damage. Contact experts if the issue remains unresolved.

 

Trust Maintracts Services For Baxi Boiler Repairs

If you're facing challenges with your Baxi boiler or need professional advice, Maintracts Services is here to help. Our fully qualified engineers are local experts in London, ready to provide a swift and reliable solution. Here's why you should choose us:

• Local specialists with deep knowledge of Baxi boilers
• Rapid emergency response when you need it most
• Clear, upfront pricing. No hidden surprises

Whether you need a Baxi boiler repair or urgent emergency boiler support, we are here to provide fast, reliable service to keep your home warm and safe. Call us now on 020 8682 2244, and we're ready to assist you.