
hello it is possible that the main pipe is closed circuit the water with the temperature expanded and not being able to back off the plastic connection when putting galvanized you solved at the moment but you can have a bigger problem, control the temperature do not mix the water and notice that the pipe is an open circuit or places expansion vessel greetings
You are right, Mariotti, the problem happened again, but it happened later where there is a c-pvc pipe, I will have to do what you mention, put a vent thanks for your help.
That was the solution a vent was installed and I no longer had the problem, thanks for the help.