Okay I am totally new to having a boiler. Just bought a house thas about 100 plus years oldand went to turn on the heat the other day and about 15 min later I find my basement looking more like a sauna. Here is a little backround to the story. We found this house and after we put our bid in someone broke in and stole some of the copper. The guy we bought it from had a team of contractors staying here after that till we closed. They replaced the copper. I talked to the contractors one day and they mentioned that whoever stole the copper never turned off the pump so that got replaced to. So now I am having a prob with the heat and I start checking things out. I bled the lines and fired it up again it starts out about 15 psi and starts climbing once the temp gets about 140 the pressure is at almost 30 soon after the valve will pop and there is where the steam comes from. One thing that is confusing me is the pump which is towards your the bottom of the boiler has a flow arrow pointing up which leads to the valves for my 4 zones. But the valves all have arrows pointing down. Could this be the problem? Which one is right?