Some iron tube radiators not heating after new boiler in

MikeCB

I replaced an old boiler with a new mod-con and now 2 of the radiators do not heat up. All were bled of air of course. I could even feel heat entering one while bleeding water out, but it did not continue to heat up on its own. I am not the installer, just homeowner. I think the installer was stymied. The water flows in a black iron loop in basement with a narrow neck piece right around each outlet and return for each individual radiator. Water was drained, flushed and a magnetic filter placed in line. Make sense? Any suggestions would be appreciated. Thanks

EBEBRATT-Ed

Sounds air bound.

Post a few pictures of the boiler stand back so we can see and a radiator pic and piping pic at the radiators and in the basement

PC7060

MikeCB said:

I replaced an old boiler with a new mod-con and now 2 of the radiators do not heat up. All were bled of air of course. I could even feel heat entering one while bleeding water out, but it did not continue to heat up on its own. I am not the installer, just homeowner. I think the installer was stymied. The water flows in a black iron loop in basement with a narrow neck piece right around each outlet and return for each individual radiator. Water was drained, flushed and a magnetic filter placed in line. Make sense? Any suggestions would be appreciated. Thanks

What is the type and GPM of the new pump? Is it possible that radiator line is obstructed in some manner, possibly on the return line?

I experienced a issue recently with one radiator not heating after I had added Sentinel 1000 into pox-mixer located on that line. The dense undiluted Sentinel just sat there as the water found easier paths to travel. This was never an issue with old B&G circulator but the new Alpha2, configured to move "just the right amount" of water didn't have the oomph to push through the mixture. Solved my issue by flushing the Sentinel out of the line using the pot-mixer hose line connection although cranking up the Alpha2 to a higher level may have worked too.

MikeCB

I'm trying to see if this is posting or not.
What is air bound?

MikeCB

They did not really change the black iron loop that feeds the radiators. New Taco pumps though. Old 007 and now new 007