That is, the second photo looks good, where a black tip comes out that is the reset button, what I do if the client gives me permission I make a hole so you can squeeze it without the need to disassemble everything and with a stick touch it push it to make it work again.
Remember to keep pressure once you circulate the water before plugging in all the air from the hot water tank and the water circulating normally through the outlet pipe (hot water)
What I am telling you is important, since if it is not well placed and has air inside and does not circulate well the water will jump again.