I have a Bryant 350MAV036060 natural gas furnace. The blower is running non-stop, but there is no ignition. Also, there is no power at the thermostat. I tried resetting the furnace by turning it off for about 5 minutes then turning it back on, but the only thing that happens is the blower starts up again. I put in a new filter, and checked all the vents in the house and made sure they are open and clear. Could someone point me in the right direction? Thanks.

One of the limit devices has opened, most likely the one in the center of the cell panel, behind the gas control, with 2 red wires attached. If the air filter is clogged and the unit is overheating, it will cause this device to open and run the blower until the unit cools. It is intended to reset automatically, but repeated cycling of the control over a long period can cause it to stick open. Try this: Turn off power, remove the control (2 screws and 2 wires), and tap the disc against a hard surface (like the floor) a few times. It may reset, but should be replaced ASAP.