I need to repair the seals of the automated water valve on my Aquastar, on-demand water heater. However, two very difficult to reach stainless steel screws have seized up and I cannot turn them without further stripping the Philips head. The location prevents me from grabbing the head with vise-grips or other pliers.
Can I, over time, apply lubricant to the few exposed threads in the hope that it unlocks the threads? Should I grind down the head into a square that I can fit some socket over? Is there some other way to get this screw out?
I am planning on waiting until the summer to effect these repairs, when hot water isn't so critical!