Fire goes on and off. cold air blows. Single blink indicator light-reads-lockout-check furnace. It appears when you change temp the flame comes on but goes out, does this twice then fan comes on and blows cold. Single blinking light comes on. I then brought temp back down-light off runs fine. Put in new filter-batteries in thermostat, cleaned leads on pressure switch and brown wired relay? Got a new thermostat- Same crap. Can someone help?