Hello all,

I am looking to add a radiator in one room of my basement. The room is 12x20 three outside facing walls, non insulated. Basement is 75% below grade. Winter temp in this room can get as low as 55 degrees. I see myself having two options, add a zone, or tap into existing system. After doing much reading about my system I am starting to get more confused, not better educated!

Hydrotherm HC-85B 68,000 BTU boiler, cast iron radiators all on the first floor. The first potential problem I find is that there are many unused, capped off monoflow tees! From what I read this is not a good thing. The system has 7 cast iron radiators, each one uses one monoflow T and one regular T. What I found was that at each radiator there is an extra monoflow and regular T. Why? no idea, this is how I bought the house.

Since I have all of the extra T's can I use them to run extra radiator(s)? Can I mix a baseboard radiator with the cast iron? all of the main radiators feed off the pipe located at the basement ceiling, the new radiator would need to have the pipe come down off the ceiling pipe and back up.

This is the direction of system flow: boiler, living room, hallway, kitchen, bedroom 1, bedroom 2, bathroom, dining room, circulator pump, boiler. This new radiator would be between bedroom 1 and 2.


I just want to keep this room warm since it is now housing quite a few fishtanks ranging from 50 gal to 600 gallon!


Thanks in advance for taking the time to read all of that!