airbound I think

rasco

First time post, please help.  Boiler issues, almost 1300 dollars in repairs and plumbing bills.  Cast iron boiler that needed a new expansion tank as the high pressure valve kept releasing.  Air was definitely introduced during the replacement process and likely had been introduced due to the old expansion tank going (it was old and might have been diaphragm-less).  There is no heat in 4 of the 7 main floor radiant baseboard heaters.  It is a cast iron boiler with an auto air vent and only one zone with shutoffs to isolate the circulator and one drain inside the boiler.  There are manual vents on all of the main floor vents and a couple of accessible vents in the ceiling of the basement (there could be hidden ones as almost all of the ceiling in the basement is finished.  The auto valve spits out a sparse amount of air occasionally and I have gotten very little air out of the manual vents upstairs and most of that is cold clear water, water out of the high pressure valve is blackish.  I did get some air out of one of the vents upstairs by lifting and rattling the line a bit and then it ran black for a time with some warmish water but now it is cold.  I have bled all of the vents I can find and I have tried purging the system by connecting a hose to the drain in the boiler and letting city water course into the system both at partial pressure and full and I got some bubbling that way but I didn't let it run to clear as the bubbling was sporadic and I was told not to put too much water in.  Sorry about the long post but I am at a loss with what to do.  I was pumping away but the plumber told me that it needed to pump towards so that got switched.  He won't fix the issue now or rather he says he is all booked up which means the same to me given his usual availability.  I can get pics if need be, please help.

Charlie from wmass

Pics are always good.

Are you talking away from the boiler or expansion tank?  Are all the electrical switches back on? any loose wires?

rasco

PLEASE HELP

All the electrical switches are on, no loose wires, the boiler fires and the pump runs and there are no zone controllers.  There is heat and water flow thru the whole basement and 3 of the 7 baseboard heaters upstairs.  Should I put isolation valves on either end of one of the cold baseboard heaters with a hose drain in the middle and use city water to flush out the air or just drain the spigot on the baseboard until hot water comes thru or put an isolation valve outside of the boilder with a drain in front of it to clear out the whole system with new water and push out the air knowing full well that I will have introduced plenty more water but in small bubble form instead of the large bubbles blocking flow to the cold baseboard heaters?

I am going to try to vent until the air comes out thru the manual air vents in a more concerted manner now.  Will do the soldering tomorrow unless someone has some hints.  Will also take pics and send later.

Please help

Charlie from wmass

Boilers usually have there own water feeds

the hose bibbs/ boiler drains are for letting out the air not forcing in water. are there any little chrome valves on the baseboards upstairs?

rasco

yes there are

I have been bleeding those little things for hours this week trying to get air out and have only gotten a small amount of air out.  I tried purging the system by removing the pump and blasting water out of the line that way.  I tried removing the manual vents on a couple of baseboard heaters to get more flow thru and it comes cold and then heats up.  This does not last.  It seems as though there are two loops and one of them is not circulating due to air and now could be from frozen lines.  I have a plumber coming on Monday.  I was told that I could put valves on either side of a locked up baseboard heater with a hose bib in the center to purge out the locked piping from either direction.  That is the last thing I can think of/was told to do.  I didn't get pics today will do so tomorrow.

Thanks so much for any help

Charlie from wmass

It does not sound like an air issue

Did you need a new pump?