Flame sense without gas valve
Low flame signal for a rectifying flame sensor requires a dcma check to check the flame rod. A visual check of the flame around the flame rod is needed to see if the low signal is caused by a poor flame envelopement of the sensor or not.
Flame sense without gas valve says that a flame sensor circuit signal was being received too long after the 24V to the gas valve power was shut off. A 24V check of the gas valve when the thermostat shuts it off will prove is the gas shut off is instant or delayed.
Either a faulty gas valve or a mother board could cause both of these fault codes.
Last edited by how; 03-17-2012 at 01:21 PM.