Hello All. I have a question related to near boiler piping and I'm disappointed that I didn't have a sketch or full pictures prior to work being started. I had a 45 year old American Standard atmospheric steam boiler that was recently replaced by an HB Smith with a Becket Power burner. The problem started at the beginning of heating season when I got a call from tenants saying that their master bedrooms and kitchens were getting no heat. The building is 5 stories, 5 full floor apartments with the living room and hallway accounting for about 40 % of the space, and a small bedroom , bathroom, kitchen and master bedroom accounting for the other 60%. There are 5 large radiators in the living rooms all on one riser. The bathrooms have just risers, and the kitchens and master bedrooms each have a riser with medium sized radiators. AS you can see from the sketch, I believe... from a picture that has obstructions, that the way the near boiler piping was configured was as is shown in sketch "A." When heating season started, and I received the complaints, I saw that the configuration they left is with was as was shown in sketch "B".... The boiler room is about 15 feet from the living room riser, and the bath, kitchen and master bed risers are 10, 25 and 40 feet from the boiler room. When i told the contractor, they sent a tech ( who was not the mechanic on the job) who pumped the pressure up to 6psi and killed most of my air vents. I replaced them all with variable heat timer vents ( 15 radiator, and one on the top of the bath riser.) The mechanic who did the work came the next day and said he would be back in a few days to reconfigure the piping. When he reconfigured the piping, he left the system as shown in sketch "C." When we fired back up, all the risers got hot, but there is still a balance issue. I got am infrared gun and shot the radiators and saw timing issues for heat and started adding additional air vents on the risers ( as per prior great advice from this site..) and I even added a second air vent on the master bedroom radiators. I Still get complaints from the last master bedroom saying they are not getting enough heat, long enough... and the room shoots at 69 to 70 degrees when the living room is getting 74 or 75 degrees. Should I ask them to fix this? Tie the two sides back together? add valve in the living room riser supply out from the boiler? I am afraid to do anything now while it is so cold.. but what is the best test to determine the right near boiler configuration. The plumber that did this 45 years ago either knew what he was doing, or, went through the same issues and piped the system to resolution.... your thoughts are much appreciated as always!