Problem with cast Iron to Baseboard

Poconoplumber

I had a house freeze and cracked every cast iron radiator.  Homeowner wanted to opt for changing to baseboard due to pricing.  System has a 2 pipe direct return.  Most of the piping going to 2nd floor reduces to 1/2".  Getting good heat on 1st fl. but  VERY inconsistent on second.  I did valve each 1st floor baseboad to adjust flow and put on a multiple speed circulator.  System does not have an air vent or diaphragm expansion tank (steel air tank).  Changing that is my next plan of attack and considering moving circulator to supply side.  I tried purging and bleeding the system and 2nd floor still troublesome.   I could use some advice in trouble shooting circulation problems.  Thanks

Mark Eatherton

Water is like my ex-brother in law, the water skier...

Wet, lazy and stupid :-)



You had to TELL him where you wanted him to go. All he wanted to do was catch another ride around the lake.



The water in your heating system is pretty much the same. It is attracted to the pump, because that is what is causing the water to move around. With everything being in parallel, the water wants to follow the path of least resistance, and go back to the pump for another ride.



You have to create equal paths of resistance in order to guarantee proper flow throughout the emitters.



The best way (not the least expensive) would be to install non electric TRV's on the individual emitters, and as they are satisfied, they shut down, sending flow to the next bigger open hole until the Tstat is satisfied. A thermally compensating self balancing system that will give GREAT comfort and reduce energy consumption by 20 to 30 percent.



Power purging a parallel system is tough as well. You have to purge each loop individually, starting at the lowest branch, closest to the heat source, then working your way outwards, then moving to the next floor, and again start with those units closest to the heat source, and working your way outwards until all the air is gone. If you try to purge with all valves open, again, the water gets lazy and stupid on ya...



Another word of caution. If the HO lived in the home with the cast iron emitters, they are NOT going to be as comfy as they were before. The MRT within the house is going to be much lower than it used to be with the cast iron emitters, so be prepared for the slew of complaints. And this MAY be the case on the second floor. Even though the air temp shows 70 deg F, the MRT is lower, so consequently, the bodies in that space do NOT feel comfortable as they use to be. The upper floor has more heat loss than the lower floor, which compounds the problem of maintaining comfort.



You've got your hands full :-)



ME