Re: thermostat info
New black thermostats are already updated from the original white ones. The thermostat seal ring in pressed into a stainless steel cup. Remove the seal, better yet get new ones, and scrape out any salt, sand, or corrosion buildup behind it. Get new rubber diaphragms also. A service bulletin said to remove the stainless steel cup and use a one-piece rubber seal, but a few years later, a new bulletin said to put the old style cup and seal back in.<br /><br />If the powerhead was replaced with a newer style one, you may have late model thermostats and housings installed, which are different from your originals.