Baxi E133 Fault

Baxi E133 Fault

The Baxi E133 fault code is indicative of an issue related to the gas supply. This error is triggered when the boiler attempts to ignite but fails, often due to problems with the gas supply itself, the ignition process, or a fault within the boiler’s gas valve system. It’s a critical safety feature designed to prevent the boiler from operating without a stable gas supply.

Causes of the E133 Fault Code

  1. Gas Supply Issues: The gas supply to the boiler may be turned off, or there may be low gas pressure in the line. This could be due to issues with the main gas supply or the gas meter.
  2. Ignition Failure: Problems with the boiler’s ignition system, such as faulty ignition leads or electrodes, can prevent the boiler from igniting properly.
  3. Faulty Gas Valve: The gas valve controls the flow of gas to the burner. If it’s faulty or fails to open, the boiler won’t receive the gas needed for ignition.
  4. Blocked Flue or Condensate Pipe: Although less common, blockages in the flue or a frozen condensate pipe can affect the boiler’s ability to ignite.

Troubleshooting and Resolving the E133 Fault Code

  1. Check the Gas Supply: Ensure that the gas supply valve is fully open and that other gas appliances in the property are working. If they’re not, there may be a wider gas supply issue that your gas supplier needs to address.
  2. Reset the Boiler: Try resetting the boiler as per the manufacturer’s instructions. Sometimes, a reset can clear temporary faults and allow the boiler to ignite.
  3. Inspect the Ignition System: Look for any visible signs of wear or damage to the ignition leads or electrodes. However, diagnosing and repairing ignition system components should be done by a Gas Safe registered engineer.
  4. Check the Gas Valve: The operation of the gas valve typically requires professional diagnosis with specialized equipment. If the valve is suspected to be faulty, it will need to be repaired or replaced by a qualified technician.
  5. Examine Flue and Condensate Pipe: Ensure there are no blockages in the flue and that the condensate pipe is not frozen. A frozen condensate pipe can often be thawed carefully using warm water.
  6. Seek Professional Help: Given the nature of the E133 fault, involving gas supply and combustion systems, it’s advisable to contact a Gas Safe registered engineer to safely diagnose and fix the issue.


The Baxi E133 fault code is a significant safety warning that requires prompt attention. While basic checks can be performed by the homeowner, resolving the issue often necessitates professional intervention. Regular maintenance and servicing by a qualified engineer can help prevent such faults, ensuring your boiler operates safely and efficiently.