Rheem Furnace 2 flashes: What It Means & How to Fix It
Compiled & reviewed by the HVAC Flash Codes editorial team · Updated 2026-06-25 · confidence: high
🟢 Often homeowner-fixable
What does Rheem furnace 2 flashes mean?
Pressure switch open — the negative pressure-switch circuit is open (the switch did not close while the inducer runs). Most often caused by Blocked, disconnected, or pinched pressure-switch tubing.
What your furnace LED does. The diagnostic light blinks 2 flashes, pause, repeat — that pattern is Rheem furnace 2 flashes.
What Rheem furnace 2 flashes means
Pressure switch open — the negative pressure-switch circuit is open (the switch did not close while the inducer runs).
Common causes
Blocked, disconnected, or pinched pressure-switch tubing
Blocked flue/vent or intake (debris, ice, nest)
A weak or failed inducer (draft) motor
A failed pressure switch
Homeowner-safe steps to try
Check that the outdoor intake and exhaust terminations are clear of snow, ice, leaves, or nests
Replace a clogged air filter to restore airflow
Cycle furnace power once at the breaker to allow a retry
Do not open the burner area, move the tubing, or bypass the pressure switch
When to call a licensed HVAC technician
If the basic checks below don't clear the code, the fault recurs, or anything involves the gas valve, burners, flame sensor or wiring, stop and book a licensed HVAC technician. Repairs to the combustion or gas system are not DIY.
⚠️ Safety first. Gas furnaces burn fuel and produce combustion gases. If you ever smell gas (a rotten-egg or sulfur odor), hear hissing, or your carbon-monoxide alarm sounds, do not touch light switches, thermostats, or the furnace — leave the home immediately and call your gas utility's emergency line or 911 from outside. Homeowners should limit themselves to simple, safe steps: setting the thermostat, checking and replacing the air filter, confirming the furnace switch and breaker are on, keeping supply registers and return grilles open, and clearing snow, ice, or debris from outdoor vent and intake terminations. Never bypass, jumper, or reset safety switches (limit, flame-rollout, or pressure switches), never open the gas valve or burner compartment, and never attempt combustion, electrical, or control-board repairs yourself. Error codes point toward a problem but are not a substitute for proper diagnosis — when in doubt, turn the system off and call a licensed HVAC technician. Keep working carbon-monoxide detectors on every level of your home.
When to call a pro: Call a licensed HVAC technician if the code returns after clearing obvious vent blockages — pressure-switch, inducer, and venting diagnosis require a pro. If you smell gas, leave and call your gas utility or 911 from outside.
Rheem furnace 2 flashes FAQ
What does Rheem furnace 2 flashes mean?
Pressure switch open — the negative pressure-switch circuit is open (the switch did not close while the inducer runs).
What causes Rheem furnace 2 flashes?
Common causes: Blocked, disconnected, or pinched pressure-switch tubing; Blocked flue/vent or intake (debris, ice, nest); A weak or failed inducer (draft) motor; A failed pressure switch.
Can I fix Rheem furnace 2 flashes myself?
You can safely try: Check that the outdoor intake and exhaust terminations are clear of snow, ice, leaves, or nests; Replace a clogged air filter to restore airflow; Cycle furnace power once at the breaker to allow a retry; Do not open the burner area, move the tubing, or bypass the pressure switch. Call a licensed HVAC technician if the code returns after clearing obvious vent blockages — pressure-switch, inducer, and venting diagnosis require a pro. If you smell gas, leave and call your gas utility or 911 from outside.
Sources: my.rheem.com · my.rheem.com. General information for homeowners, not professional advice — confirm against your furnace's manual and a licensed technician.