I changed the expansion tank today and now I'm wondering if I need to bleed the system or is it ok to turn it back on. The last time the heater ran was during the home inspection when I was buying the place in spring. Steps I took. 1. Turned gas off to the heater 2. Turned the heater off (turned off electric to the unit) 3. Turned off water to the heater 4. Removed and replaced expansion tank (old tank was rusty and weak at the inlet) The old tank had quite a bit of pressure/water in it. I definitely got wet. I'm not sure about all of the components. I know one is the reducer valve for the water pressure and I'm pretty sure the other is a purge valve/bleeder, but I don't know if it's auto or manual. And if it is auto do I still need to do a manual bleed after changing the tank? If so what steps do I need to take? Here's some pics of the system. If you need more pics of specific areas let me know. [Old Tank](https://pic8.co/sh/84X3Ku.jpg) [Reducer Valve](https://pic8.co/sh/oFYaBg.jpg) [Purge Valve/Bleeder ???](https://pic8.co/sh/mT5Jnk.jpg) Whole System - https://pic8.co/sh/a6FOA9.jpg - https://pic8.co/sh/XGrqg8.jpg The box on the pump is open because some water got in there so I'm trying to dry it out before turning the power back on. Any help/input is appreciated. I plan on replacing the boiler next summer with a forced air system. At least then I'll know how to work on the damn thing if something goes wrong. Just gotta make it through this winter.