Came out to a no heat recall. I found that the wire coming from the spark igniter was rubbing up against the gas valve and causing the wire to arch and not send voltage to the igniter. We wrapped the compromised wire in electrical tape and ran the system. The igniter then sparked and the system came on. We ran that unit for 20 minutes and it ran to specifications. We also check the other unit because it came on and went off immediately while we were there so we checked the flame sensor and it was dirty. We cleaned the flame sensor then ran the system and everything is working according to specifications.