Inside temp is 48 degrees, hard to type.. turned power off and waited and then turned back on with Trane VX90 furnace only 2 years old. Blower works but only cold air. Green light came on, it sounded like it was trying to work, then red light blinks three times (the portal glass you look through).. any suggestions? I would LOVE HEAT tonight and not have to call repair tomorrow..
Thanks a lot

Check the hot surface ignitor. If it doesn't glow, current won't flow to the gas valve. The ignitor and gas valve are connected in series. They are easy to replace, just make sure to turn the power to the furnace off first and don't touch the grey surface of the new ignitor upon installation. Replacement ignitors generally go for around $25.50, including shipping, on eBay.