Lennox Heat-pump 71509 Error Code — Meaning & Causes (2026)
Heat pump outdoor coil temperature sensor is reading outside the expected range. Below: what triggers it and what to check — this code carries no single repair to price. Reviewed July 2026.
What 71509 means
Heat pump outdoor coil temperature sensor is reading outside the expected range.
Likely causes, most common first
- Failed outdoor coil temperature sensor
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
71509 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 heat pump 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).