looping cast iron radiators

Joe_101

I have a gravity fed system and I'm replacing the old boiler. I want to dual zone the house with the new boiler. Can I loop the cast iron radiators? If not, how do I pipe the new system?

Thanks

Timco

Are you familiar with how to pipe the new exp tank, and convert to circulators? It depends on how long the loops will be ( or better how many rads and what sizes)and what size. You may need to go with a two-pipe method if the loops are too long. You will also need a two-zone controller. Please follow the recommended piping instructions found in the manual, and ask here for details. Sometimes the mfg's recommendations need some tweeking near the boiler.

Tim

PHM

Why are giving up the gravity system ?


I understand chnaging the boiler, but why are you going to a full pumped system?

PHM
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Joe_101

I want to finish the basement and the old pipes hang down to about 6' 4" from the floor. iwant to raise the pipes so I can install a drop ceiling. Also I feel we'll have better temperature control in the hosue.

Mike T., Swampeast MO

The only piping changes that will need to be made are right around the boiler.

Do not "loop" standing cast iron radiators in series!

Presuming you have two pairs of mains from the boiler (common), if you're extremely lucky each main pair may serve something approaching what you want for "two zones". In the more likely event that each main pair serves nothing similar to your desired zones, either leave unzoned or install thermostatic radiator valves (TRVs) on all radiators. TRVs ensure that all of the radiators behave as a single system (as seen by the boiler) while giving room-by-room zone control (as seen by the user).