I have a Day/Night forced air heater and the burners will not light. The fan runs but the igniter glow device does not turn red and the gas valve does not open. I have run the on test mode and the igniter glows red but when turned on by the thermostat the igniter does not work. I have checked the thermostat and it works fine and also have replaced the igniter.
Is there a switch or a relay that may be out and not be sending a signal to the igniter?

Thanks

Exact model number of unit?

Number of flashes showing on the circuit board?