Boilers · every brand

Boiler won't light

An ignition code means the boiler tried to light and couldn't, or lost the flame. The cause is often outside the boiler: the gas supply, or in winter a frozen condensate pipe.

  • 14 codes
  • 4 brands
  • Often easy to fix

The code on each brand

Same fault, different code. Each one opens a page with the maker's own checks and a verdict.

Can't read yours?

Worcester Bosch EA 227 No flame detected

The boiler couldn't detect a flame, so it has locked out.

Usually free

Worcester Bosch EA 229 Flame lost while running

The burner lit, but the flame went out while the boiler was running, so it has locked out.

Usually free

Worcester Bosch EA 234 Gas valve electrical fault

The boiler has found an electrical problem with its gas valve, such as a coil that's disconnected, so it has locked out.

Get a quote first

Vaillant F28 No flame detected when lighting

The boiler tried to light but didn't detect a flame, so it has locked out.

Usually free

Vaillant F29 Flame went out and won't relight

The flame went out while the boiler was running, and it couldn't light again.

Usually free

Vaillant F27 Flame detected with the burner off

The boiler sensed a flame when the burner should have been off.

Deal with it now

Vaillant F62 Flame went out too slowly

When the boiler shut off the gas, it detected the flame going out later than it should have.

Deal with it now

Baxi E133 Won't light: gas supply or frozen pipe

The boiler tried to light and couldn't, so it has locked out.

Worth fixing

Baxi E128 Flame keeps going out

The boiler has locked out because it lost its flame too often.

Worth fixing

Baxi E135 Gas supply interrupted

The boiler lost its gas supply, or found an internal fault, and stopped.

Usually free

Baxi E151 Flame failure

The burner flame failed or wasn't detected, so the boiler stopped.

Usually free

Ideal F2 Flame loss (went out or won't light)

The boiler lost its flame or couldn't light, so it has stopped.

Worth fixing

Ideal L2 Ignition lockout (boiler won't light)

The boiler tried to light and couldn't, so it has locked out.

Worth fixing

Ideal L6 False flame lockout

Ideal lists L6 as a false flame lockout: the boiler has sensed a flame when it shouldn't have, and has locked out.

Get a quote first

Check these first, whatever the brand

  1. Check your other gas appliances

    If the hob or other gas appliances don't work either, the problem is the gas supply, not the boiler.

  2. Check the meter

    On a prepayment meter, make sure there's credit left. Check that the gas valve next to the meter is on.

  3. Frozen condensate pipe?

    In freezing weather, check the plastic pipe that runs outside from the boiler. If it's frozen, thaw it with warm water, then reset. See frozen condensate pipe.

  4. Reset, but only as the manual says

    Press reset and wait. Makers say to try only once or twice: repeated resets won't fix a real fault.

When it's time for an engineer

If gas is reaching the boiler and it still won't light after a reset, a Gas Safe engineer will check the ignition electrode, the flame sensor and the gas valve.

Questions people ask

Why won't my boiler light?

Most often the gas supply, such as a prepayment meter out of credit or a closed valve, or in freezing weather a frozen condensate pipe. Otherwise a part such as the ignition electrode or flame sensor may have failed.

How many times can I reset my boiler?

Follow your manual. Most makers say to try once or twice. If the fault keeps coming back, call a Gas Safe engineer.

Another code on the display?

Look it up in seconds

344 codes from 24 brands, each one checked against the maker's own manuals and support pages.

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