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.

Qty	Possible Causes:
1	Bad Control Board
	Sticking Gas Valve
	Shorted Flame Sensor

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