Trane Furnace CL2.020.01 Error Code — Meaning & Causes (2026)
Retry — the flame sensor does not sense flame (after 3 retries in the same call for heat the control locks out). Below: what triggers it and what to check — this code carries no single repair to price. Reviewed July 2026.
What CL2.020.01 means
Retry — the flame sensor does not sense flame (after 3 retries in the same call for heat the control locks out).
Likely causes, most common first
- Flame sensor not sensing flame (less than 1 microamp)
- Inlet or outlet gas pressure too low
- Flame sensor not positioned properly in the flame
- Burner crossovers not aligned properly or restricted
Base: 1 published national repair-cost guide (retrieved 2026-07) · full source registry on the methodology page · Code meaning & causes · Reviewed July 2026
No single repair to price for this code
CL2.020.01 doesn't point at one failed component, so we don't attach a price module — forcing a repair mapping here would be dishonest. If the code keeps returning, the underlying symptom (not the code) is what gets priced: browse the gas furnace repair costs for the problem you're actually seeing.
Codes are universal — your location changes the repair price, never the code's meaning. See the methodology for the exact localization formula and sources.
Reviewed by a Red Seal–certified appliance technician who also holds a Technical Safety BC gas ticket (Gas-C) and an ODS/halocarbon refrigerant ticket (CFC/HCFC/HFC).