EE0 Lockout - too many ignition retries (3)

What the control is telling you

The control tried to light the burners 3 times and failed (no flame proven, or flame lost after lighting), so it locked out. The flowcharts call this code E0.

Applies to: Daikin DR96TN (upflow/horizontal) and DD96TN (downflow/horizontal) two-stage 96% furnaces with 9-speed ECM motor, R-32 ready

Likely causes

• Gas supply off or interrupted, gas valve switch OFF, or low inlet/manifold pressure
• Hot surface igniter not glowing, cracked or out of position
• Dirty or oxidized flame sensor / weak flame signal
• Vent or intake pipe blocked, too long, too many elbows or wrong termination; weak inducer
• 90% models: front cover (coil cover) pressure switch opening because the condensate trap or drain is blocked or not primed
• Poor ground or reversed line polarity (control cannot sense flame)

Test and repair steps

1. Read the active code (Err menu) and the fault history (L6F menu) on the 7-segment display; cycle the thermostat to retry and watch the full sequence.
2. Confirm the inducer starts and the igniter glows for the whole warm-up. No glow: check for 115 VAC at the igniter during warm-up - if voltage is there, replace the igniter.
3. Igniter check (power off, igniter at 70-77 F): silicon nitride igniter should read 37-68 ohms. 80% models with the carbide mini igniter: 30-300 ohms.
4. If the burners do not light gas valve switch ON, 24 VAC at the valve during trial for ignition, inlet pressure 4.5-10.0 in. w.c. natural gas / 11.0-13.0 in. w.c. LP with all appliances running.
5. Check manifold pressure while firing natural gas high fire 3.2-3.8 in. w.c., LP 9.7-10.3 in. w.c. (see the Gas pressure table for each model).
6. 90% models: make sure the front cover pressure switch stays closed - prime and clear the drain trap, check the switch hose for kinks or water, and check vent length, elbows and termination.
7. If the burners light then drop out measure flame current with a DC microamp meter in series with the sensor - normal is 1 to 4 microamps. Clean the sensor with steel wool and check its position in the flame.
8. Check grounding and polarity a reversed hot/neutral or a high-resistance neutral can cause flame-sense lockouts.
9. Make sure manifold pressure stays steady during the run and does not drop below the range.

Settings for these units

• Normal status displays (7-segment) · Daikin DR96TN/DD96TN