Replace Schrader Valve or Entire Air Vent?

[CTnewbie]

Hey Everyone,

For those that don't know me, I'm new to the HVAC-R field, fresh out of Tech School, still looking for employment. In the mean time I'm picking up work from friends who know I've recently graduated from school. This evening I went to a house where they were complaining of a leaking boiler. First thought was expansion tank, but when I actually looked at the boiler I noticed the leak was coming from the Taco Air Vent. I unscrewed the cap to the air vent and I could see the the Schrader Valve gasket was deformed. It looked like it was pulled out a little. My question for those of you that know a lot more then me is should I just replace the Schrader Valve or just replace the whole Taco air vent? I would think just the valve, but I wanted to see if I was correct first.

Thanks for any help you can provide!

[dynamic098]

Hi Joe, it is not actually a schrader valve that is in the can. There is a scoop in the water stream that collects the air. When enough air has been collected, the float releases the air through the top. You could try to "rap" the can on the sides with a heavy wrench to see if you can dislodge a possible stuck float. If not you will need to replace the high vent, which means isolating and draining the system. Caleffi has a high vent that has a check valve with it. By putting the check valve in, if it ever leaks again, you can just unscrew the vent and replace without having to drain the system down.

[ascj]

You don't need to drain the system. It's 1/8" threads. Just bring the loop pressure down to 0psi and swap it on the fly.

[Joehvac25]

Or just screw the cap down tight, if there is no air in the system it would be fine until they acualy have to drain it for some reason then replace it

[CTnewbie]

Okay, that makes a little more sense. I was trying to understand how a schrader valve would work with a air vent since a schrader valve is meant to keep air in, lol. But there is some type of valve on top. When I pushed the pin, more water came shooting out. And I'm certain the gasket around the valve is shot since I can see half a loop sticking out of it. I'll just go to the local supply house tomorrow and pick up a whole vent. We did a lot of work with hydronic in class, switching out all types of things so I'm pretty good with isolation the zones and bleeding only part of the system, lol. I would add a check valve but this air vent is actually in the casing of the boiler, and it would be a lot more work to get in there to add the valve then it would just to drain a little water from it.

Thanks for the help!

Hi Joe, it is not actually a schrader valve that is in the can. There is a scoop in the water stream that collects the air. When enough air has been collected, the float releases the air through the top. You could try to "rap" the can on the sides with a heavy wrench to see if you can dislodge a possible stuck float. If not you will need to replace the high vent, which means isolating and draining the system. Caleffi has a high vent that has a check valve with it. By putting the check valve in, if it ever leaks again, you can just unscrew the vent and replace without having to drain the system down.

[craig1]

You don't need to drain the system. It's 1/8" threads. Just bring the loop pressure down to 0psi and swap it on the fly.

Real men just do it on the fly with the system at full pressure.

[Joehvac25]

Real men just do it on the fly with the system at full pressure.

I usually bump it up to 29 psi and 200 degree water myself!

[kangaroogod]

They are kidding

[Joehvac25]

They are kidding

Whoops forgot what were dealing with here lol

[CTnewbie]

I tried to do it without draining the loop as suggested but black water started spraying all over their brand new white carpet. I'm not sure what I did wrong. I did as you guys suggested, lol

[Joehvac25]

I tried to do it without draining the loop as suggested but black water started spraying all over their brand new white carpet. I'm not sure what I did wrong. I did as you guys suggested, lol

You have to let the pressure off but not totally drain it

[hvacvegas]

Real men just do it on the fly with the system at full pressure.

with an 1/8 thread that wouldn't be hard. I did that on a radiator in a huge building. Coin valve though, not auto bleeder.

Semi-finished space, basically threw drops on the ground and made a tent out of drop clothes.

Worked out pretty good actually.

[Tecman1]

To swap a Hy Vent and change it on the fly expect some leakage. I would protect the space if it is finished but this is a major time saver.

[dlove]

get the pressure off the system, remove the valve and replace it with a small ball valve or bleeder valve, plug it...I hate those auto vents..I cant see a lot of air in the system once its up and running...this way they will not get any surprises when the valve blows off and floods the house.

[SuperTech2010]

Real men just do it on the fly with the system at full pressure.

Hell yes!!!! go getem its just water no freon here.....if ur going to drain the system plug the vent and install the honeywell air ELIMINATOR..if you ever use this, you will never use a bleeder again.

[CTnewbie]

You have to let the pressure off but not totally drain it

LOL, I was just kidding in my above post. I closed all the loops, drained a little water out until the valve stopped leaking, then carefully removed the valve just to make sure I let enough water out of they system. Everything went well, and no mess, lol.

Also, let me that everyone for the replies!

[calubeda]

Real men just do it on the fly with the system at full pressure.

Do you know any of them? One of the installers I help learned to lower the pressure on the boiler trying full pressure. I usually close the isolation valves and get some water out.