Best Of

It isn't an emergency but I would try to do it as soon as you can reasonable schedule it. You could probably get through the season on that if you absolutely had to but it isn't the recommended course of action.

Make sure the LWCO and water feeders work.

That is a single dry return. If it were to drop to the floor and run along the floor to the boiler, it needs that vent that is at the boiler to be moved to where it drops to the floor.

The condensate that forms in the radiators and in the main itself runs toward the end of the main because it is all pitched that way then it follows that dry return below the main back to the boiler.

The air in the main also follows that dry return toward the vent at the boiler where it is vented out.

You might want to get "We Got Steam Heat" to learn the basics of how steam systems work.

flood it and see where the water comes out

Could be a flange gasket where the pipe covering blows up in size or a union but most likely the boiler. Flood it when it is cold as others have mentioned.

@mattmich and @ethicalpaul , the other part of the equation is……. balance.

You want the steam to reach the ends of all the mains, not only quickly, but also at about the same time. Once you accomplish that, the steam is available at every tee where a radiator connects, and will rise to all the radiators at the same time. Balancing the heat in all the rooms is easy when you do it this way.

This is where "pipe math" comes in. Once we know how much air is in each main, we have our starting point for sizing vents. Occasionally we need to make changes from the original sizings, but having that starting point gets the job done faster.

And @ethicalpaul and @mattmich I agree with you both! And for another look at it, Cedric is a fairly decent sized boiler (fires at 3.3 gph). The system is fairly decent sized (total of arund200 feet of 2 and 2.5 inch mains).

And the whole show is vented with a stable pressure of 2 ounces per square inch gauge by one Hoffman 75 and one Gorton #2…

My own way of figuring it is different — I look at pressure profiles rather than times — but the end result is the same.

My concern over the copper is not based on the copper itself as it is probably fine. My concern over using copper is that it "points to" may have been installed by a "hot water plumber" versus a "steam fitter" who would likely stick to black pipe. Hot water plumber may not be aware of or take pipe pitch seriously

The change in diameter from Steel to Copper of the same size is not an issue.

Can't tell from pics but the copper pipe in the second picture running back to the riser probably is run flat as there is no swing joint. The hammer could be in that location. The bottom of the riser should have a swing joint and be pitched back to the boiler. You can get away with 1 pipe being flat but if you have 2 pipes flat that causes issues especially if the rises goes up a distance as you will get more condensate in the riser flowing down faster on a cold start

The Gorton is a larger vent maybe slowing the venting could calm things down and make it workable.

Do you know the size of the copper pipe and what the EDR of both radiators is? Looks like maybe 1 1/4" which is good for 55EDR 1" is good for 25EDR?