Circulator Pump Problem

Yanks2009

Hi Everyone,

I have a steam boiler that feeds steam heat to radiators on the second floor of my house and a hot water baseboard loop on the first floor of my house. The system is on two zones (there is a thermostat for the first floor to control the baseboard and a thermostat on the second floor to control the second floor radiators).  I have a Bell & Gossett circulator pump which feeds the loop.

Recently, the B&G pump has been making a loud rattling noise.  I also notice that it is not pumping much hot water into the baseboard loop.  Only part of the loop is getting warm.  Meanwhile, the radiators upstairs have been getting hot with just the first floor thermostat on. 

A couple of weeks ago I had to cut and re-solder a pipe on the loop. It is possible that I introduced air into the system which is creating the problem.  However, for about a week following the work I did on the piping, the baseboard heat was working fine. Also, I  tried to bleed a vent on a hot water radiator connected to the loop (which appears to be the highest point)  to let some air out of the system, but it hasn't helped

Does anyone have an idea what the problem may be? Could it be that the pump is dying?  Thanks for your help.

DanHolohan

Here's the info on that.

http://www.heatinghelp.com/article/17/Hot-Water/76/Condensate-Hot-Water-Heating



Sounds like you lost the prime.