Reasons for failure of cast iron rad to heat up after re-piping?
As part of our kitchen remodel, the plumbers replaced the two vertical cast iron pipes going up to the cast iron radiator in the room above with Pex lines installed in the wall. Instead of the original pipes going straight up vertically, and then a short cross to each end of the radiator above, the Pex lines go up vertically between the studs in a wall about 6 feet away, then cross the 6 feet over to the original connections where the cast iron pipes went up into the radiator above.
They've refilled that zone of the system, and that's the only radiator that is stone cold. All of the others on the zone heat up.
The plumbers are suggesting putting in some sort of pump/regulator to pump to that radiator. Before they do that, I'd like a GardenWeb sanity check that what they're suggesting makes sense. :-)
- Is there any "directional" to these hot water cast iron radiators? I mean, do the need to make sure that what was the intake on one end in the original feeder pipe is the same intake in the replacement one? That it's feeding the same end of the radiator as it was before?
(I know there is for steam, however, this is hot water/radiant).
- Given that this radiator was working fine before, what about the new set-up would make it go cold now? The width of the Pex being smaller diameter? The greater horizontal distance going to the radiator from the vertical pipes now?
- Anything else that I should have them investigate before they jump to putting in this regulator item?
Thanks in advance!