Taco Air Vent Leaking

The air vent riding above my boilers air separator and expansion tank has suddenly begun to leak water from the air bleed, and I have shut if off (screwed it down tight). Any ideas as to why this might happen?

Most likely it has a piece of dirt or rust scale under the seat, or the seat is worn out depending on the age and how often it opens. On mine they can be taken apart and cleaned, if that wont work they are not terribly expensive and easy to replace.

Bk

Thanks! I'll pick up a spare before attempting to fix it. The leak is minimal, but persistent.

lsayre wrote:Thanks! I'll pick up a spare before attempting to fix it. The leak is minimal, but persistent.

When you replace it, put a shut off valve between it and the air separator. You will need to repalce it again and it makes it much easier.

coalkirk wrote:When you replace it, put a shut off valve between it and the air separator. You will need to repalce it again and it makes it much easier.

Excellent advice. Thank you!!!

Unless there's already a shut off under the vent they can be a pain to replace. You need to drop the pressure off the system....or at least let it cool down & prepare to take a shower. It's amazing how much water can floe from a small hole at 18 PSI. When you drop the pressure, you risk letting air into the system & now you must purge each and every zone....unless all zone have valves & you took the time to close them all, then purge the header pipe. But, for sure, spend the extra $2.80 and put a mini valve under the vent...do ALL the vents is there's more than one.

Freddy wrote:Unless there's already a shut off under the vent they can be a pain to replace. You need to drop the pressure off the system....or at least let it cool down & prepare to take a shower. It's amazing how much water can floe from a small hole at 18 PSI. When you drop the pressure, you risk letting air into the system & now you must purge each and every zone....unless all zone have valves & you took the time to close them all, then purge the header pipe. But, for sure, spend the extra $2.80 and put a mini valve under the vent...do ALL the vents is there's more than one.

I have 3 vents. Only the one is leaking.

Replace all three while your at it. Save yourself some aggravation later. If one is leaking the other two can't be far behind!

blrman07 wrote:Replace all three while your at it.

I wouldn't necessarily do that, but, I most certainly would put a valve under each one. I think I might buy a spare vent for the shelf, but I wouldn't use it til I needed to. Vents are quirky little fellows.... some will go about forever, others seem to leak in a short time.

coalkirk wrote: When you replace it, put a shut off valve between it and the air separator. You will need to repalce it again and it makes it much easier.

Freddy wrote:Unless there's already a shut off under the vent they can be a pain to replace. You need to drop the pressure off the system....or at least let it cool down & prepare to take a shower. It's amazing how much water can floe from a small hole at 18 PSI.............

Why weren't these tips posted before ????

Drop the temp and pressure ???? No, I wanted to get a bath with hot water and then attempt to hold my thumb over the hole until that got too hot so I removed my thumb.... you see where this is going...............

Never thought about the little valve.

I think I will be doing that to each vent this summer when I do the rebuild.

Great great advice. That is why I love this forum so much.

Rick

Rick, search Yanche's old posts...he has recommended the isolation valves for a long time and posted picture.

Webstone makes a nice valve/drain setup for an expansion tank.

Rob.

I was looking at this as something to use on the bleeders on the radiators. Not for the expansion tank. I already have a valve there.

Here we have bleeders on each and every radiator. Within the past few years, I have replaced every bleeder with "automatic" bleeders. Prior to we still used the old keys to bleed them.

Rick