I have a Trane XB80 gas furnace and the fan works but the burners don't even try to come on. I had a similar problem last year and the tech came out and found an improperly installed filter that was clogged. After removing the filter, he restarted the furnace. It worked for a couple of days, then stopped working again. He came back out and reset it, same thing, worked again for a couple of days, then stopped. A week ago, I turned the furnace on, and it worked.This morning, no burners, just the fan and four flashing leds. I have replaced the filter, cleaned the flame sensor, and jumpered the two dime size switched and the rectangular plate. I'm wondering if it just needs to be reset. I have shut off the circuit breaker several times, but I still get the four flashing leds after start up. How do you reset the furnace?

Replace batteries in thermostat

There should be a key to the blink code somewhere on the furnace. It is often on the inside of the blower door, sometimes on the board itself. Please let us know what the 4 blink code means.