EEA Reversed line polarity or grounding error

What the control is telling you

The control detected that the 115 VAC hot and neutral are reversed, or the unit ground is poor. The furnace will not operate.

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

Likely causes

• Hot and neutral swapped at the furnace or panel
• Poor or missing ground wire
• Transformer primary/secondary out of phase

Test and repair steps

1. Warning: line voltage present - use care when measuring.
2. Check that the black (hot) and white (neutral) supply wires land on the correct terminals; correct the polarity.
3. Confirm there is a ground wire from the furnace j-box right back to the panel. Gas pipe or conduit does not count as ground.
4. Power off and measure resistance from the neutral (white) connection to the burner nearest the flame sensor - it should be very low (the manuals give less than 2 ohms and also 10 ohms or less).
5. If an unmarked transformer was replaced, check phasing: about 96 VAC between the connected primary/secondary leads means in phase, about 144 VAC means out of phase - reverse the low voltage leads.

Settings for these units

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