i have a ravenheat 82e that wont go to main flame. The pilot lights but the igniter keeps going and then it all stops and the pilot goes out and goes into flame lockout after about 20 seconds. my igniter only has 1 wire on but it says in the manual that i have a flame sensor but i can find one. is the ignitor also the flame sensor? the igniter part number is 5021050. can anyone advise me further please