Rheem RGRA-07EMAES Error Code 1 Blink: Soft Lockout

What Does Code 1 Blink Mean?

A single blink of the green STATUS LED on the Rheem RGRA-07EMAES is the UTEC 1012-925 Integrated Furnace Control (IFC) reporting a soft lockout. The board ran four complete ignition trials and never confirmed a stable flame, so it shut the sequence down. On this control the gas valve is energized for only 7 seconds per trial, which gives the flame sensor a narrow window to prove the burners actually lit.

Because the RGRA-07EMAES is a single-stage furnace, every attempt is a full-rate light-off with no low-fire fallback, so a weak or dirty flame-sense signal turns into a hard failure quickly. After the second failed trial the main blower and induced-draft motor purge for 180 seconds before the board retries. Once the fourth trial fails, the furnace holds a one-hour lockout and then retries automatically; cycling furnace power forces an immediate restart instead of waiting out the hour.

The most common cause on this board is a flame sensor coated with oxide or carbon that can no longer pass the small microamp current the IFC needs to confirm flame. That same buildup usually shows up first as a slow-blinking amber FLAME LED (marginal flame sense) before it escalates into this 1-blink lockout, so the two codes are directly related stages of the same problem. A manual gas shutoff valve left in the OFF position is the next most common cause. A weak 115 VAC hot surface igniter, no gas flow, or a defective gas valve are less common and are technician repairs.

What You'll Notice

• No heat, and the furnace falls completely silent for up to an hour after a burst of activity
• The green STATUS LED flashes once, pauses, then repeats the single blink
• The igniter glows and the inducer spins, but the burners never light or light briefly and then drop out
• You hear the inducer and blower run for about three minutes between attempts before the furnace gives up
• Only cool air, or no air, comes from the registers because the burners will not stay lit

Common Causes

How This Is Diagnosed

Diagnosis follows the Rheem flowchart from the safest, most common cause outward. First confirm the manual gas shutoff valve at the furnace is open, because a closed valve produces the identical four-fail lockout. Next the flame sensor is cleaned and its position in the burner flame is checked, since rod buildup is the leading reason the IFC never confirms flame within its 7-second window.

If a clean sensor and a confirmed gas supply do not clear it, the remaining checks are technician work: verifying the 115 VAC hot surface igniter actually glows and reaches temperature, confirming gas flow and correct manifold pressure, and testing the gas valve. Those steps involve live line voltage and gas pressure and are not homeowner tasks.

How to Fix It: Clean the Flame Sensor and Confirm the Gas Supply

What You'll Need

• 1/4-inch hex head or nut driver
• Scotch-Brite pad
• Flashlight

Steps

1. Turn off electrical power at the breaker and shut off the gas supply valve Set the furnace circuit breaker (or the furnace power switch) to OFF, then turn the manual gas shutoff valve to OFF with the handle perpendicular to the pipe. If you smell gas, leave immediately and call your gas company.
2. Open the access panel and locate the flame sensor Remove the burner-compartment access panel and look near the burner assembly. The flame sensor is a thin metal rod, usually bent at an angle, mounted on a white porcelain insulator with a single wire and one mounting screw.
3. Remove the flame sensor Disconnect the wire, remove the mounting screw, and carefully pull the sensor out. Handle it by the porcelain insulator or bracket, never by the rod itself.
4. Clean the sensor rod Gently clean the flame sensor rod with a Scotch-Brite pad until the metal is dull-bright. Rheem's guide lists fine steel wool as the cleaning material, but many HVAC technicians prefer a Scotch-Brite pad because it leaves no abrasive residue on the rod. Do not clean or scratch the white porcelain base, and take care not to bend the rod.
5. Reinstall the flame sensor Seat the sensor back in its bracket, secure the mounting screw, and reconnect the wire. Confirm the rod will sit in the flame path when the burners ignite.
6. Confirm the gas supply is on Check that the manual gas shutoff valve near the furnace is open, with the handle parallel to the pipe, so the burners receive gas on the next trial.
7. Restore power and test Turn the gas valve back ON, set the breaker or power switch to ON, then set the thermostat to call for heat and watch the full ignition sequence.

When to Call a Professional

Contact a licensed HVAC technician if:

• The burners still fail to stay lit after the flame sensor is cleaned and the gas supply is confirmed on
• The igniter does not glow at all during the ignition sequence
• You can hear or smell gas at the burners but it never ignites
• The furnace keeps returning to the 1-blink lockout after each reset
• You smell gas near the furnace at any time

✓ Verified against manufacturer service manual — March 2026