Air purger leak

That gold contraption is your air purger. There is a float inside that drops down to open the valve on top to release any air captured by the scoop below. They fail periodically for various reasons. It could be because the float developed a leak or most often some debris is fouling it up. I removed one a few years back that I was able to disassemble and repair. What had happened was the hot boiler water scavenged all the soldering flux that had been used in assembling the system and deposited it in the purger where it solidified. (I've improved my soldering skills since)

I suggest you wait 'till you can shut the boiler down and REPLACE it. I now, never install a purger without first installing a ball valve between the system and the purger. Those 1/8" ball valves are usually available at your local plumbing supply outlet.

I've had this problem before but my air purger was 30 years old and assembled with hems not threads..So I recentally had to buy more automatic air vents (they go for about 5 dollars each) the new ones appear to be threaded BUT the instruction sheet states that they need to be replaced when they start to leak,and they are not serviceable..Maybe you can nurse it through this year then replace it, if you are going to try to tighten it, do it on a cold system and have a new vent in hand just incase it gets ugly..Dave

Oh, I see now where the leak is after reading Taco's post. Don't touch it 'till Spring, when you can shut the system down. Remember to install a ball valve so you can replace it anytime.
I'm surprised Taco's lasted 30 years.

Hi Reaperman,
Some of the newer can vents come with a valve built in so that you don't have to buy a shutoff valve. It just threads in between your air purge and the can vent. When the can vent is screwed into the fitting, it then opens the valve.

reaperman said:

Because I'm sure the water is going to fly when I screw the old one off.

Click to expand...

Shut off the inlet water, let the whole system cool, and then de-pressurize the system by opening a drain, and then close the drain- once you do that, relatively little water should come through the 1/8" opening for the air vent, because there won't be any pressure pushing it, and nothing should really drain or siphon out a hole that small, at least not very fast.