TACO Air Vent Purges Water!

[Solid]

Hey guys,

As you can see by the amount of posts on Plumbingforums.com, my house is a disaster area! Anyway, I noticed a small amount of water puddled near my boiler, and it is coming from the top of this TACO air vent:

I though this device was supposed to purge air from the forced hot water heating system, but this one leaks water. I'm assuming that it is a problem with the air valve, and not something else. This valve was very inexpensive, so I just ordered one from Pex Supply. I'm wondering if you guys can help me with the process of replacing this? I'm not sure how to properly shut this system down, and then turn it back on after the part has been replaced. I can figure out how to shut off the system (power off the boiler), and shut off water to the system, and there are a few spigots that I should be able to use to depressurize the system, but I'm wondering what the proper sequence would be?

Thanks!

 

[Solid]

I searched the web a little, and I found this guide to replacing the vent:

How to replace an auto vent

It's pretty generic, but does that sound right?

 

[johnjh2o]

I can tell you how we replace them but without experience you could get into a little trouble. First turn the power to the boiler off, then turn the feed valve off. Open a drain valve to drop the water pressure on the boiler. (don't drain the boiler just drop the pressure) Then very quickly remove the old vent and screw the new one in. You will get very little water when you remove the old one, as long as no air is allowed to enter the system. What happens is you a pulling a vacuum on the system. (like holding your finger over a straw) After the vent is installed turn the feed valve back on. Then turn the power on.

John

 

[Solid]

Thanks for the reply. I'm planning on having my boiler serviced this spring/early summer - do you think I should just ask the service tech to replace it? Do you think we will not want to do it because I already have the part?

 

[Solid]

Johnjh2o,

It's go time for this job my friend. The temps have warmed up and I can go without heat if need be. I went down there tonight and turned off the boiler, and closed the water supply. I'm really not sure how to relieve the pressure in the system. I unscrewed the valve slightly and the water started to leak out - more than I think I can deal with. I do see some spigots (not on the boiler, but on the individual zones), can I open one of those just to lower the pressure? There is a gauge on the front of the boiler, and I can see it isn't at zero.

 

[johnjh2o]

There should be a drain on the boiler. (look low) Connect a hose to it and open it up. Both the boiler and the supply valve should be off. You don't have to drain all the water just until the pressure on the gauge zeros out. Remove the old vent and install the new one quickly. You will get some water but there should be no pressure. There will still be water in the system but it will be like holding your finger over a straw, no water can flow as long as no air is allowed into the system.

 

[Solid]

Johnjh2o,

Thanks for the instructions, everything went fine, and no leaks!

Another question (maybe I should open another thread?) - I would like to replace both the 90's in the image below, because one has a couple holes in it. Is this something I can just go buy at the local box store and install?

 

[johnjh2o]

Yes you can but if your speaking about the dent on the lower ell that was put there by a service tech so he could put a instrument in there to check the burner. Good job on the vent replacement.