Hi. At one point, I used the hot water and it began to make a very loud internal noise, and after a while it began to lose water from above, without having at the top any exhaust valve (the lid seal was broken). Can I fix it by changing the thermostat and repairing the cracking with some sealant product (and passing a purge) ??? In the photos attached, I think I understand that one is the purge key (blue key) and I don't know if the other connection (bronze color) is a relief valve. Will we have to change some of that too? IMG_20200118_152825.jpg [1.22MB] IMG_20200118_152817.jpg [1.28mb]