Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

air purging problem in baseboard loop system

JK_3 Member Posts: 240
It sounds as if you have some type of a restriction,mabye a valve closed that some one forgot to open or forign matter stuck somewhere. after installationby on of my techs one time and many hours of trying to solve this problem we found that while unloading materials one length of pipe had a very solid dirt clog in the end of the lenght that went unnoticed. you could try pluging the relief valve(with the system off and cold of course) and raise the pressure to purge through your #2 purge.do not exceed the max pressure of the lowest rated componant that will be exposed to the pressure.

<A HREF="http://www.heatinghelp.com/getListed.cfm?id=417&Step=30">To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"</A>

There was an error rendering this rich post.


  • Tony N.
    Tony N. Member Posts: 1
    air purging problem in baseboard loop system

    We just installed 48 ft of cast iron baseboard radiators to heat the lower level of a garage building in center city Philadelphia (approximately 800 sq ft). There is an older cast iron oil boiler that feeds the baseboards. Right now the boiler keeps going off on high limit and only first 10 feet or so of supply piping gets hot. There is a TACO 0010 circulator pumping away from a # 30 Extrol tank. There is also a TACO 007 on the return piping near the boiler. Both circulators are energized at the same time. There is a single loop of 3/4" copper which that includes about 100 feet of copper, including the supply and return (not including the 48 ft of baseboard). The problem is, I believe there is an "air lock" in the loop that we cannot seem to eliminate, despite having two separate purge lines. One is on the return line close to the boiler (purge valve 1) and the other is on the vertical section of return line that goes from the last baseboard up through the basement ceiling and into the garage (purge valve 2)--the pipe runs about 10 feet along the garage floor before elbowing up into the boiler return. All of the baseboard radiators have bleeders, which were bled. We have no trouble purging the air out of the purge valve 2 (near the last section of baseboard), but purging air from the next 15 feet of pipe run from purge valve 2 (near the boiler) is a problem. We cannot seem to get the water to flow over these last 15 feet of return pipe (5 vertical and 10 horizontal). When we use the boiler feed valve to feed through the supply piping and back up into the return, we get nothing (no air and no water) to come out of purge valve 2. The only way we can get air out of this section is to force it through the purge valve 2 and into purge valve 1. What often happens then is the pressure relief valve opens and the circulation problem re occurs. Is it possible that city water pressure is not adequate to fill this loop? I'm really stumped on this one.
This discussion has been closed.