OEM Carrier Flame Sensor for PY3PNA042090AA Furnace Replacement Part

The flame sensor is a single metal rod that sits in the burner flame and proves — through micro-amp flame rectification — that a flame is actually present after the gas valve opens. When it gets coated with oxide and carbon buildup, the signal drops and the control board closes the gas valve within seconds as a safety measure. The signature symptom: the furnace lights normally, runs for 3–7 seconds, then shuts off, and repeats (short-cycling) until it locks out. No heat despite a furnace that clearly ignites is the giveaway. This is a single-rod rectification sensor; a healthy flame signal reads roughly 1–6 microamps DC in series with the burner flame. The rod and porcelain insulator are matched to the burner geometry so the tip sits correctly in the flame envelope. A reading below about 0.5 µA means insufficient signal. Rod length, bend, and insulator placement matter — a generic sensor that positions the tip slightly off the flame produces a weak, drifting microamp signal and intermittent lockouts that are maddening to diagnose. OEM geometry guarantees the rod sits in the hottest, most ionized part of the flame for a stable, reliable signal. Install difficulty: 1/5. Tools: 1/4" nut driver, and a multimeter set to DC microamps to verify the flame signal afterward. (The old sensor can sometimes be cleaned with fine emery cloth, but a pitted rod should be replaced.) #1 SAFETY WARNING: turn OFF the gas and the electrical breaker before removing the sensor. Ships same business day from our stocked warehouse on orders placed before 3 PM CST. Backed by a 1-year OEM warranty and 30-day hassle-free returns on uninstalled parts.

Compatibility

This part is compatible with Carrier model PY3PNA042090AA. Always verify the part number against your unit's data plate before ordering.

Why Choose OEM?

OEM parts are manufactured to the exact factory specifications for your unit. Generic aftermarket alternatives may fit physically but often use lower-rated components that reduce equipment life and void manufacturer warranties. When the cost difference between OEM and generic is $10-30, the OEM part is always the smarter investment on a system worth $5,000-$15,000.

Shipping & Returns

Same-day shipping on orders before 3 PM CST. Standard delivery 2-5 business days, express options available at checkout. 30-day hassle-free returns on uninstalled parts — free return shipping included. 1-year OEM factory warranty coverage.