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Lennox · Error codes

Lennox GCWB95 133 — Ignition Failure (5 Attempts)

133

LockoutLennox GCWB95 condensing combination boilers (numeric error messages, user's information manual 240012894)

Ignition failure (5 attempts). Ignition failed after 5 attempts; press the RESET (R) button for at least 2 seconds and call an authorized service technician if the fault persists. The table classifies it as Error.

Applies to

This ignition fault code is displayed by the GCWB95 control (numeric error display with RESET) on GCWB95 models (GCWB95W-150, GCWB95W-205 wall hung combi and GCWB95F-150 floor mount combi), as documented in Lennox GCWB95 User's Information Manual, PN 240012894 Rev. A [04/15/2020], Section 3.6 error messages (models GCWB95W-150, GCWB95W-205 wall hung combi and GCWB95F-150 floor mount combi) (240012894 Rev. A). Codes can differ between controller generations, so always check the manual that matches your unit.

Controller: GCWB95 control (numeric error display with RESET). Source manual: 240012894 Rev. A (2020-04-15).

Why a code is not a diagnosis

An ignition code says the burner did not prove a flame when it should have; it does not say why. Gas supply, ignition components, grounding, venting and the control module each need testing on site.

Safe things to observe

  • If you smell gas, stop, go outside and call your gas utility's emergency line or 911 before anything else.
  • Note the exact code and what the appliance was doing when it appeared.
  • Check whether other gas appliances in the building are working.

Do not

  • Do not keep resetting to force more ignition attempts.
  • Do not open the gas valve, touch ignition components or bypass any safety device.

How professional service helps

  1. A licensed gas technician tests gas supply pressure and the shut-off state.
  2. The ignition probe, lead, gap and grounding are inspected against the manufacturer's specification.
  3. Combustion and safety devices are verified with an analyser and the manufacturer's procedure after any repair.

Where ROMA provides on-site service

On-site service is currently offered in Greater Vancouver, BC, including Vancouver, Burnaby, Richmond, Surrey, Coquitlam, North Vancouver, West Vancouver, New Westminster, Port Coquitlam, Port Moody, Delta, Langley, Maple Ridge, Abbotsford, Chilliwack, White Rock, Pitt Meadows, Tsawwassen, Anmore, Lions Bay, Belcarra, Bowen Island, Mission. Everything else on this site is reference information you can use anywhere in Canada.

See all service areas

Parts and service

Parts commonly involved

These parts appear in the documented text for this alert. A code reports a condition, not a failed part — a technician confirms the cause by testing before anything is replaced.

Service for this alert

  • Gas Boiler Repair

    Licensed gas technicians from ROMA Heating & Cooling diagnose and repair residential and light-commercial gas boilers across…

  • Emergency Boiler Repair

    Priority gas boiler repair for homes and buildings in Greater Vancouver with no heat, no hot water, a locked-out boiler or a leak.

Every boiler part explained — what it does, how it fails and what a technician checks.

Documented for Lennox Lennox GCWB95 (gas-fired condensing combination water boiler).

Frequently asked questions

Does this code mean I have a gas leak?

Not by itself. If you smell gas, stop, leave the building and call your gas utility's emergency line or 911 from outside before anything else. Otherwise the code points to a fault a technician confirms on site.

Can I clear this code myself?

Clearing a code without fixing its cause usually just brings it back. Note the code, check the safe items on this page, then call a licensed technician. If your appliance manual describes a user reset for this exact code and it stays away, no call may be needed.

Boiler locked out? Call with the alert text ready.

The brand, model and this alert are passed along when you request service online, so the technician arrives prepared.

On-site service in Greater Vancouver, BC. ROMA lists “Open 7 days” on its site; call to confirm same-day availability.

Sources and verification

Facts checked September 9, 2026. Last updated September 9, 2026. Technical reviewer: not yet assigned.

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