Rheem RGPH-07EAMGR Error Code 1 Blink (2-sec pause): 1 Hour Lockout

What Does Code 1 Blink (2-sec pause) Mean?

The 1-blink status code on the Rheem RGPH-07EAMGR indicates the furnace has entered a 1-hour safety lockout after failing to ignite in 4 consecutive attempts. During each attempt, the gas valve is energized for only 8 seconds — if flame is not detected within that window, the attempt is counted as a failure.

After all 4 attempts fail, the blower and induced draft blower will run for 100 seconds to purge any residual gas, then the system shuts down for 1 hour. After the lockout period expires, the furnace will automatically retry.

The most common cause is a dirty flame sensor. The sensor rod develops oxide and carbon buildup over time, which reduces its ability to detect the small microamp current that passes through the burner flame. When the sensor cannot confirm flame presence, the control board shuts off the gas valve as a safety measure. Other causes include a gas supply valve that is turned off, a defective hot surface igniter that is not reaching sufficient temperature, or a faulty gas valve.

Common Causes

How to Fix It: Clean the Flame Sensor

What You'll Need

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

Steps

1. Turn off electrical power at the breaker and shut off the gas supply valve Locate the furnace circuit breaker and flip it to OFF. Turn the gas shutoff valve to the OFF position (perpendicular to the pipe). If you smell gas, leave immediately and call your gas company.
2. Locate the flame sensor Open the furnace access panel and look near the burner assembly. The flame sensor is a thin metal rod (usually bent at an angle) mounted with a porcelain insulator. It typically has a single wire connected to it and is held in place by one screw.
3. Remove the flame sensor Disconnect the wire from the flame sensor. Remove the mounting screw and carefully pull the sensor out. Handle it by the porcelain insulator or mounting bracket, not the rod itself.
4. Clean the sensor rod Gently rub the metal rod with a Scotch-Brite pad until it is clean and shiny. Do not use regular steel wool alone, as it can leave fragments. Do not bend the rod or damage the porcelain insulator.
5. Reinstall the flame sensor Place the sensor back in its bracket, secure the mounting screw, and reconnect the wire. Ensure the sensor rod will be positioned in the flame path when the burners ignite.
6. Verify the gas supply is on Check that the manual gas shutoff valve near the furnace is open (handle parallel to the pipe).
7. Restore power and gas, then test Turn the gas supply valve to ON and flip the circuit breaker to ON. Set your thermostat to call for heat and watch the ignition sequence.

When to Call a Professional

Contact a licensed HVAC technician if:

• The burners still fail to stay lit after cleaning the flame sensor
• The hot surface igniter does not glow during the ignition sequence
• You can hear gas flowing but it does not ignite
• The furnace keeps entering 1-hour lockout repeatedly
• You smell gas near the furnace

✓ Verified against manufacturer service manual — March 2026