Keston · Legacy Keston Heat 45 and 55 commercial boilers · United Kingdom, Ireland and Romania

IGNITION LOCKOUT error code

IGNITION LOCKOUT – legacy Keston Heat 45/55 error code

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Quick answer

What does Keston Legacy Keston Heat 45 and 55 commercial boilers IGNITION LOCKOUT mean?

Keston documents “Ignition lockout” for the legacy Heat 45, 55, 45P and 55P controller. This is a distinct earlier product generation from the Heat² range and must be matched to the exact boiler display.

The code identifies the condition detected by the product; it does not always identify the failed component on its own. Confirm the full code and exact model before ordering parts or attempting a reset.

The Keston Legacy Keston Heat 45 and 55 commercial boilers IGNITION LOCKOUT error code indicates keston documents “Ignition lockout” for the legacy Heat 45, 55, 45P and 55P controller. This is a distinct earlier product generation from the Heat² range and must be matched to the exact boiler display. This guide explains what the code means, the symptoms and likely causes, the checks that are safe to make, and when to stop and arrange an authorised repair.

Symptoms you may notice

The boiler displays IGNITION LOCKOUT; burner or heating operation may be blocked or locked out until the underlying condition is corrected.

Common causes

Possible causes are associated with ignition lockout, including the related circulation, sensor, combustion, fan, electrical, safety-interlock or controller circuit described in the official fault-finding guide.

Before you start troubleshooting

Use the display, rating label or product menu to confirm the exact model. Similar-looking codes can have different meanings across product generations and regions.

  • Record the complete code before switching the equipment off.
  • Check only user-accessible controls, filters and external connections described in the manual.
  • Do not open gas, refrigerant, combustion or electrical compartments.

Troubleshooting steps

Check that gas is available and the external condensate pipe is clear; professional checks cover the ignition, flame-sensing and gas-valve circuits.

Can you fix this error code yourself?

The safest next step depends on the exact model and the cause behind the code. External checks may help, but a returning fault needs professional diagnosis.

A successful reset is not proof that the underlying issue is fixed. If IGNITION LOCKOUT reappears, note when it happens and give that information to the service engineer.

Reset instructions

Record the exact message first. Reset only after the underlying cause has been corrected and never continue resetting a recurring fault.

Applicable products and models

Keston Legacy Keston Heat 45 and 55 commercial boilers Heat 45; Heat 55; Heat 45P; Heat 55PLegacy Keston Heat 45 and 55 commercial boilersHeat 45; Heat 55; Heat 45P; Heat 55PLegacy generation to 2020

When to contact a professional

Contact Keston commercial support or a suitably qualified Gas Safe registered engineer when the message persists or requires internal tests, measurements, wiring checks or component replacement.

Frequently asked questions

What does Keston Legacy Keston Heat 45 and 55 commercial boilers IGNITION LOCKOUT mean?

Keston documents “Ignition lockout” for the legacy Heat 45, 55, 45P and 55P controller. This is a distinct earlier product generation from the Heat² range and must be matched to the exact boiler display.

Can I fix Keston Legacy Keston Heat 45 and 55 commercial boilers IGNITION LOCKOUT myself?

Some external checks may be suitable for the user, but the result depends on the exact model and cause. Use the official manual and arrange service if the code returns.

Should I reset the product after code IGNITION LOCKOUT?

Record the exact message first. Reset only after the underlying cause has been corrected and never continue resetting a recurring fault.

When should I arrange a repair?

Contact Keston commercial support or a suitably qualified Gas Safe registered engineer when the message persists or requires internal tests, measurements, wiring checks or component replacement.