No Main Vents?

jamesylove

I have a 1 pipe steam system and  have had some issues getting it balanced. I wanted to check the main vents.  However, I've been unable to find any main vents in my basement.  The basement is finished, but I can see all of main pipes, except the last section of main that that feeds that last radiator to my 2nd floor.  I can access this section of pipe by removing a section of drywall.  Is it worth the effort to do this and discover a potential main vent (I'm not very hopeful that one exists)?  If there is no vent, should I try to add a vent at this location or another location on the main?  I've learned a great deal on this site and appreciate any advice.

nicholas bonham-carter

where is the vent?

use a level to determine the slope of your main. if it is sloping up away from the boiler, then it is a counter-flow, and the vent should be on the end. if it is sloping down from the header, and back around towards the dry return, the it is a parallel flow, and the vent should be at the end of the dry return.

every system needs some way for the air to get out of the main pipes, and since the radiator vents are not up to the job, without a lot of expensive help from the fuel company, main vents are needed. so it is well worth the digging in to the ceiling.--nbc

jamesylove

Old main vent?

I removed a section of drywall near the end of the main.  The section

pictured below is about 2' from the last riser that feeds the furthest

radiator on the 2nd floor and about 18" from the end of the main before

it turns down as the return.  Do you think this fitting used to be a

vent?  Currently, it is just a plug on the fitting.  Should I try to remove the plug

and install a vent since I've been unable to find a vent anywhere else

on the main.

jpf321

angled take-off

normally, a T which is angled on the main like that usually was meant for a radiator takeoff somewhere that was perhaps never installed or removed .. this may be a good place for a vent .. but there probably was not a vent there originally, more likely a radiator. you will probably have a really hard time taking that plug out. 

jamesylove

Thanks...

Thanks for your reply, I'm going to try and remove the plug on the T.  However, as you can tell from the picture, I do not have a lot of room to work so I may not have enough leverage.  But, if I can remove the plug, does the vent need to be perpendicular to the main?  i.e. do I need to use another fitting to correctly position the vent on the main

Dave in QCA

Vent installation

You vent needs to be installed vertically, otherwise the float mechanism in the vent will not be able to work correctly.

jamesylove

Stuck plug

I've soaked the plug with penetrating oil and have used my 18" pipe wrench but I can't break it loose.  I don't have room for a larger wrench or a bar on the wrench.  I may heat up the Tee and try to loosen it in the next couple of days.



Plan B: since I do not have a main vent I think I may try to tap into the main next to the Tee and add a vent.  What are the chances that I somehow damage this section of main by tapping this old pipe?  Should I call a pro to add a vent?