Leaking Air Valve

I dropped water in my boiler a few months ago and now that winter is coming I went to fill up again.

I was not getting any pressure and could not bleed the radiators. I checked and saw no pressure. I reverse-filled up to 15psi but the air valve (not the pressure relief) leaked out water. It came out in a real thin stream. When I shut the little knob on top it stopped, but Im pretty sure that I should not leave that shut. So I am keeping my boiler off for now.

But anyone know why it is leaking?

This is not my valve, but is the same type:
http://inspectapedia.com/heat/Autovent_MOM_218_DJFs.jpg

It is on a T, coming from the boiler, and another end of the T is going to an expansion tank.

Should I have closed the valve that leads to the expansion tank before reverse filling? Now that I think about it, by reverse filling with the valve to the expansion tank open, didnt I fill that tank too? And wont there be nowhere for excess pressure to go?

 

Why did you do that?

Do you mean by 'reverse-filled' that you hooked up a washing machine hose with a cross connection to feed water into the boiler?

Yeah, it needs replaced, but it won't hurt anything to keep it shut. You will probably hear air in the pipes but that won't actually hurt anything but your ears.

Because it's no good... those things have very limited lifetimes. Just one of those things.

No.

What kind of expansion tank do you have? Big metal tank in the joists above the boiler? Or the kind that looks like a gas grill propane tank?

 

Im not sure how to format this nice and neat like you did, so please bear with my less-clear formatting.

I removed a radiator to paint it. It was in the bathroom and too tough to reach properly with the toilet in the way. I took it out and properly cleaned and painted it.

Yes.

The kind that looks like a small propane tank.

So if I change it (the air valve), a new one should work properly? Letting out only air but not water when the system is pressurized?

 

In the bar across the top of the reply window, all the way to the right, there is an icon that looks like a cartoon 'callout' box. If you click that it will place {qoute} {/quote} in the body of the reply. Anything you put between those two will appear in a box in the reply.

OK, that's fine... I just wanted to make sure that you were not under the mistaken impression that hot water heating systems need to be drained and refilled each year. Lots of people think that and they are harming their systems by doing so.

Read this. There are instructions for properly recharging the air in those tanks. Follow the instructions step by step and don't deviate or you won't get the proper charge of air in the tank.

Before doing this though, I should also ask: Does the tank say FILL-TROL on it? If it does, these instructions do NOT apply.

http://www.doityourself.com/forum/bo...sion-tank.html

Read this one also...

http://www.doityourself.com/forum/bo...ure-gauge.html

Yes, correct. I said to just close the cap for the time being, but you do want to change it first chance you get since when you refilled the system a lot of air came in dissolved in the water that must be expelled from the system.


Can you take some pictures of the boiler and piping around it so we can see what you're working with?

 

Still working on pictures. But my tank says Extrol. So I am assuming the instructions on the other thread for pressurizing do apply.

 

Yes, that is correct.......................