Hi, I year ago I replaced my igniters on my Viking Range Model VGRC3656BBSS because I was having problems with the oven. The oven was not getting to temp and the igniter was lighting but flame was really low . All was great for a while but then my originally problem resurfaced. My igniters light but the flame then greatly diminishes. It happens a lot but not always. Some one mentioned replacing the safety valve. Do you have a source, video or directions on this?