LOOKING FOR SERVICE CODES FOR NORDYNE HEATER MODEL NUMBER GL1RA108C-20C. RED LED LIGHT FLASHES 4 FAST FLASHES,THIS IS AFTER HEATER LIGHTS RUNS FOR A FEW SECONDS THEN SHUTS DOWN THE GAS VALVE. I THINK IT IS A BAD FLAME PROVING SENSOR BECAUSE IT WILL KEEP TRYING TO LIGHT OVER AND OVER UNTIL IT LOCKS OUT AFTER SO MANY TRIES. THEN IF YOU LET THE HEATER REST A WHILE IN THE OFF POSITION IT WILL AT THAT POINT LIGHT RIGHT UP AND RUN.PLEASE HELP. SERIAL# IS GLA030700341 THANKS, RODNEY.