My current oil fired boiler [for baseboard heating] is a little over a
year old. It is the HMT model, manufactured by international comfort
products in Canada. I know this may not mean much to people out there,
but perhaps a few may be familiar with it.
The boiler has what the manual calls an "automatic air vent"
protruding from the top of the unit. This vent is gold/bronze in
color, cylindrical, with a hole on the side [presumeably for air to
seep out], and a black screw in the top of the unit.
For weeks, I had been experiencing air in my pipes so I suspected that
this "automatic air vent" was not working properly. On inspection
recently, I noticed that the screw in the top of the vent had actually
popped off. In its place was a slight amount of water dripping out of
the hole. I left it off, and noticed that when the system starts up,
there is a little more water coming out each time. My service guy
didn't seem to concerned, and simply screwed it back in. He claimed
that the air problem is unrelated to this phenomena.
Since his last visit, the air in the pipes continued. I then noticed
that the screw had popped off yet again, and continues to do so each
time I replace it. It is not immediate, but if I check in a day or so,
it is usually on the floor. In order to check things out, I have left
it out, and now notice that the air in the pipes seems to have
If anyone is knowledgeable about such things, is it possible for these
vents to clog and force air up throgh the hole where the screw is
located? Also, should the screw be in tight, or loose?