Aaron, Thanks for responding.
I ran through all of the lengthy checks that are mentioned in my first post. Your additional info has helped me establish that the amplifier is not bad.
What makes it troublesome is that everything is now okay.
My symptoms were, I would set a temperature and it would not hold. For example it was a cold morning. We headed out for an hour drive and everything heated up nicely, but it didn't stop heating. So we ended up turning it off and on as we needed it. I checked all of the fuses and they all check along with the two that were added later in the 116's life. I even turned the fuses with my fingers because of the corrasion potential with those darn fuses.
Like I mentioned in the earlier post everything is working. With my luck it's an impending failure.
Thoughts on the way to check out the regulating valve?