u/Downtown_Bet_9313

I went to a house today, pressure relief was blowing off, he has a contract that covers everything. I was always taught to check the water feeder, expansion and relief valve. Found I was feeder was letting water slip through constantly and the expansion tank was blown. I changed them out and not I can’t get any pressure in the boiler. I switched out tons of water feeders and never had this issue. I’m getting pressure before it and nothing through it. Could it just be bad? Is there an easy way to check if I even have enough pressure, I know it should have tension on the top stuck if it has enough but I don’t get why else I’m not getting water into the boiler. (Feeder is also called a pressure regulator but we always have called it a water feeders where I am) any help would be greatly appreciate I am so stumped and not sure where else to go.