Rheem Rheem R96V 96% AFUE Two-Stage Variable Speed Upflow Gas Furnace 7 FLASH Error Fix: Low Flame Signal

Error code 7 FLASH on the Rheem Rheem R96V 96% AFUE Two-Stage Variable Speed Upflow Gas Furnace means: Low Flame Signal. The flame was successfully established but the flame sensor current is below the minimum acceptable threshold (typically below 1.0 microamps DC). The furnace may operate intermittently or lock out after repeated low-signal cycles. The most common cause is a dirty flame sensor rod — carbon buildup on the rod insulates it and reduces the flame current. Remove the flame sensor (one mounting screw, one wire connector), clean the metal rod with fine emery cloth, steel wool, or a green Scotch-Brite pad until shiny. Do NOT use sandpaper, as grit can embed in the rod. Reinstall and test — flame current should read 2-6 microamps when measured with a meter in series. If cleaning resolves the issue temporarily but it recurs frequently, also check grounding (see 6 FLASH) and replace the flame sensor if it is heavily corroded.

The most successful fix is "Test and Replace Flame Sensor Assembly" (medium difficulty, ~45 minutes). Estimated DIY cost: $15-$25. HomeMD has 2 community-ranked fixes for this error.

This error is rated warning severity. It is generally not urgent and can often be resolved with a simple DIY fix.

Yes — the top-ranked community fix ("Test and Replace Flame Sensor Assembly") is rated medium difficulty and takes about 45 minutes. Tools needed: T20 Torx screwdriver, Multimeter, Fine emery cloth (optional).

DIY cost: $15-$25. Professional repair typically costs $120-$180. Many homeowners save money by trying the top-ranked community fix first.

The Rheem Rheem R96V 96% AFUE Two-Stage Variable Speed Upflow Gas Furnace has 8 other known error codes, including: 1 FLASH (Normal — Heat Call Active), 10 FLASH (Rollout Switch Open), 11 FLASH (High-Stage Pressure Switch Open (Two-Stage Only)), 2 FLASH (System Lockout — Ignition Failed), 3 FLASH (Pressure Switch Stuck Closed), and 3 more.

Error code 7 FLASH also appears on 2 other Rheem models: Rheem Professional Classic 50 Gal. 38,000 BTU Natural Gas Water Heater, Rheem R801T 80% AFUE Single-Stage Upflow Gas Furnace. The fix may vary by model, so check each model's specific page for tailored repair steps.