Carrier Carrier 59TP6A080E17 80,000 BTU 96% AFUE Two-Stage Gas Furnace with Variable-Speed Blower MECH-GAS-VALVE Error Fix: Gas Valve Sticking — Intermittent Ignition Failure

Error code MECH-GAS-VALVE on the Carrier Carrier 59TP6A080E17 80,000 BTU 96% AFUE Two-Stage Gas Furnace with Variable-Speed Blower means: Gas Valve Sticking — Intermittent Ignition Failure. The furnace sometimes ignites and sometimes doesn't. The ignitor glows, but gas doesn't always flow. The gas valve solenoid may be sticking intermittently — it opens on some cycles but not others. This is more common in older furnaces where corrosion or debris has accumulated in the valve. Other symptoms: delayed ignition (a "wump" or mini-explosion when gas finally reaches the glowing ignitor after a delay), or the furnace works fine when ambient temperature is warm but fails on cold mornings (the valve solenoid is stiffer when cold). Diagnosis: listen for the gas valve "click" about 15-30 seconds after the inducer starts. If you hear the ignitor glow but no click, the gas valve likely isn't opening. Check that 24V is present at the gas valve terminals when the board calls for it (using a multimeter). If voltage is present but the valve doesn't open, the valve is faulty. Replacement costs $200-$400 installed. A licensed technician should verify gas pressure after replacement.

The most successful fix is "Test and Replace the Gas Valve Solenoid" (hard difficulty, ~90 minutes). Estimated DIY cost: $150-$300. HomeMD has 2 community-ranked fixes for this error.

This error is rated medium severity. It should be addressed soon, but your appliance may still function in a limited capacity.

Yes — the top-ranked community fix ("Test and Replace the Gas Valve Solenoid") is rated hard difficulty and takes about 90 minutes. Tools needed: Phillips screwdriver, Adjustable wrench, Multimeter, Gas leak detector.

DIY cost: $150-$300. Professional repair typically costs $300-$400. Many homeowners save money by trying the top-ranked community fix first.

The Carrier Carrier 59TP6A080E17 80,000 BTU 96% AFUE Two-Stage Gas Furnace with Variable-Speed Blower has 8 other known error codes, including: BLINK-1 (LED 1 Blink — System Lockout (Retries Exceeded)), BLINK-10 (LED 10 Blinks — Secondary Limit Switch Open (Condensing)), BLINK-2 (LED 2 Blinks — Pressure Switch Stuck Closed), BLINK-3 (LED 3 Blinks — Pressure Switch Did Not Close (Draft Safeguard)), BLINK-4 (LED 4 Blinks — Open High-Limit Switch (Overheating)), and 3 more.

Error code MECH-GAS-VALVE also appears on 3 other Carrier models: 58STA090-1-16 90,000 BTU 80% AFUE Single-Stage Gas Furnace, Carrier 58SB0 Comfort 80 Single-Stage 80% AFUE Gas Furnace, Carrier 58STA/STX 80,000 BTU 80% AFUE Single-Stage Upflow Gas Furnace. The fix may vary by model, so check each model's specific page for tailored repair steps.