So I have an 1880s Victorian in Boston that is proving to be quite the adventure. I'm new to this, so hopefully I am using the right words.
I have a four zone hot water heating system with radiators and baseboards. One of the zones (my problem zone) covers most of my second floor and features three standing radiators -- big old Niagras.
For each of the radiators, the hot water travels up from the basement, through the radiator, and then back down to the basement. The pipe then crosses the basement ceiling and goes back up again to the next radiator. After the third and final radiator, the pipe returns to the boiler area where there's a pump to pull the water.
The first radiator in the loop is HOT. The second is lukewarm. The third is room temperature.
We replaced the old pump with a new Taco - the old one was on its last legs. We also replaced the expansion tank.
The next identified culprit is the flowcheck valve (green in photo attached).
Could it be that the flow valve is slowing the flow of water through the system? Is it more likely that the first radiator is gobbling up the heat somehow?
I've attached photos of the first radiator, the up/down pipes (just to give you an idea), and the flow valve we may replace next.
Any help/ideas for what could be wrong would be much appreciated.