Hi you all! First and foremost thanks for reading my post and I hope you can help. I have a 1 pipe steam system that has been driving me a little crazy. The water level is always off (very high) and I'm always draining it to bring it back to level and when I check a day later the same thing happens. Well, I decided to sit there with the water leveled as it should be and fired up the boiler. I noticed that the water kept getting lower and lower as the heating cycle went on and then....it happened, the low water level control went on and the burners went off. Then I heard that the water was coming back down through the return pipe into the system. However, the automatic feeder had already been prompted and now the system had water coming in from the feeder and the pipes causing for the water level to go higher then recommended. My question here is why? If the pressuretrol is damaged can this cause the problem? I know that the pig tail pipe is clean and clear and the pressuretrol is set at .5psi cut-in and 1ps cut-out. So, I'm actually at a loss here. Now, there is something else I should mention. This system was changed a couple of years back. It went from 8 radiators to 5 radiators because the house was split. It was first set up to run 4 radiators on the first floor and 4 on the second floor. Here is where it got interesting. They got rid of the first floor radiators (turned it into a separate unit) and added 1 (non vented radiator) to the attic (3rd floor) to the system. This 5th radiator was added sharing a pipe with one of the other radiators. I am mentioning this because I am not sure if this can have something to do with it. I am not sure why they added a non vented radiator to a system that runs with air vented radiators. Perhaps, this can be a problem? Please if you have any advise I will appreciate it. I am about to call the pros and let them take care of it. Although I was thinking of just replacing the pressuretrol first and then taking it from there. What do you think?

I am putting a second heater in a duplex. Should I use PEX pipe with or withour a manifold syste or just put in copper. the heater will be approx. 65 000 BTu wiith old cast iron radiators. What size should the main run be 3/4 or 1" Thanks Ed