i have a bryant plus 90 model #350mav048100 does anyone know what could be wrong the blower starts and stops clicks when heat is called but the coil wont lite i have made sure the gas is on and the valve is opened i lived in the house for 8yr never a problem i have shut the furnace down and started over also i went outside and cleared out the exhast pvc at the house so there is nothing clogging or restricting the air flow. if any solution please state where i can purchase parts thanks . EAST AMHERST NY 14051 :) could this be the board or the mechanicsim that has the gas on off looks like it is about 5inches long and maybe 3 wide with threaded gas going in and 1 going out. and if it is the board am i better off with a new furnace maybe one more efficient with the advances in technology?

I've got a Williams gas wall heater that won't fire up. It was working fine (it's about 8 years old) until last weekend then stopped. The pilot stays lit but when I turn the thermostat up nothing happens. I tried adjusting the thermostat (it's a millivolt type), then replaced the thermostat, and still nothing. Also checked all the connections and the pilot and they seem fine. Any advice on what to try next? Would a bad thermocouple show these symptoms? I hate to blow $175 on a new gas control valve (they're non-returnable out my way) if it's something simple. Thanks very much for any help.