DNZ - Flashing Code 8

Package Unit: DNZ

Re: Flashing Code 8

These units have one control board (EMCB) which controls all unit functions.

► Any heating diagnostics will be displayed on the EMCB.

CODE 8 = Flame sensed with gas valve OFF. 

If flame is sensed for longer than 4.0 seconds during a period when the gas valve should be closed, the control will enter lockout, flashing the LED 8 times.

The control will turn on the inducer and blower motor while the flame is sensed.

CHECKOUT:

1. Check Flame Sensor

• The flame sensor is in the pilot assembly.
• Make sure that there is nothing shorted against the flame sensor.
• Make sure the flame sensor is not too close to the pilot hood.

2. Check the Gas Valve

• Cycle the heat On and Off multiple times by placing a jumper between "R" and "W1".
• Ensure that the main gas AND the pilot extinguish immediately when power is removed from "W1".
  • Pilot or Main Flame Stays On = Bad Gas Valve
  • Pilot and Main Flame Go Off Every Time = Bad Control Board