Had a service call for a 30 gal lp not working right. show up and find the water heater on start-up blow flame out the bottom(its the flamelock) and after about 2min of burning the flame burns more inside the burner and glows red. called whirlpool they sent out new gas valve and burner. installed new parts, same problem. checked water colum its right. called whirlpool again and get someone who knows something, she says they are working on this problem and the have a new orfice to fix it. new part came today i installed the new size 55 orfice(the old one is a 54) and that took care of the large fire ball on start up and it burns much smoother. whirlpool called me today about the problem and told me that they switched from a cast burner to a cheap metal one and they are working the bugs out. hope this helps someone else.