I finally bled my radiators a week ago after my renter complained about the noise they were making. The noise is gone now, but now the pressure is way lower than it should be (under 10, when I think it should be more like 15 or 20). Oh, well, at least we're not freezing... yet. :worried:

Add water.

Yeah, I thought that might be a good idea. There are lots of knobs and things down there. I just have to find the right one. Thanks.

Add another problem to the list... this morning I got out of bed and was about to get into the shower when I noticed the sound of water running somewhere in the house. I started a quick check of the premesis, and found nothing amiss upstairs... so I went downstairs.

Stepped off the last step, and my foot squished into VERY wet carpet. Aw, FUCK. Opened the door into the back room, where my wife keeps some of her pets (some guinea pigs), and a water line had burst, spraying cold water all over the place. I shut off the valve, but it had been running for hours, and had already drowned many of her animals, and made a big wet mess. After several hours of wet/dry vaccing, and a quick water line replacement, the mess is reduced, but it will take a few days to get things back to normal. Bah.

I hope ditto and megmeg aren't too sick of me complaining about my house. Poor bastards.

So, back to my boiler problem. Thanks for the info, guys. I was going to look for bleeder valves today, but the other events prevented it, so I'll look tomorrow. I'll also try to ascertain if the line is copper, galvanized steel, or cast iron.
I am certain the tech didn't cause my current problems, if that's what you mean. The heat worked great when we first moved in... in fact, one section valve was stuck open (the one I've since had replaced), and it made things uncomfortably warm in that area of the house. I then shut off the boiler's power and gas supplies for the warm season, as per the manual's instructions, and it never worked very well again since I started it back up when things got chilly.

Thanks a shitload for the help, guys. Air sounds like a big possibility, I'll hunt for bleeder valves tomorrow, and let you know what I find.

No matter how much of a maze it is, there should only be 3 pipes coming off the boiler itself (unless you've got a tankless heater, then 5) so find the one that goes to the domestic water supply and figure out which valves. Watch the gage.
It sounds so easy, doesn't it. Bwahahahahaha.:)

Thanks, Bruce. Actually it was easy. I watched the gauge until it got to about 15, then shut it off. Later I walked into my bedroom and there was a great deal of brown liquid dripping from the ceiling onto my bed. (Yucky, but not as bad as H_P's latest predicament sounds.)

I had noticed a small amount of leaking earlier from the upstairs radiator. I guess when I added water, it spouted.

On this leaky radiator, the round valve handle has been broken for as long as I can remember and the water comes straight out the top of the valve (right where the handle is supposed to screw on). I was at the store today and was about to buy a new handle, but I think I should buy the whole valve assembly, no? Surely, there are seals inside the valve itself that are bad and it won't help just to screw on a new handle.

Oh, it doesn't leak at all when I shut the valve, though (using a pliers, since the handle doesn't work).

What do you think?

Does the handle screw on or is it held on with a screw through the middle of the handle into the stem? If it's the latter then I'd just put a screw in the hole.
When the valve leaks by, i.e. not stopping the flow through the radiator, then the washers and/or seats are bad. When the valve leaks out to air (mess) then it's the stem packing that's bad. There's usually a cap with a hole in it for the stem that screws on the valve like a nut and holds the stem in the valve. The stem packing goes on the stem before the cap/nut goes on.
So if the water is coming out the center of the stem put in a screw. If the water is coming out around the stem then try tightening the packing nut (that cap/nut thingy). If that doesn't work you'll have to remove the packing nut and wrap some stem packing (teflon tape works) around the stem and replace the nut. That can be pretty messy with pressure on the system, especially if you don't have experience.
BTW, any valve in the house that doesn't get moved for months (years?) at a time, it's a real good practice to loosen the packing nut before moving the valve then tighten it up again. It keeps the packing material from getting torn up and keeps valves leak free longer. Of course when the water level is between your upper lip and nostrils, I wouldn't bother with it. :)
Sorry it took so long to get back to you. Mom pulled rank.:(

The latter. Did that, then realized it not just leaking out the stem, but from the packing nut. Then I went to work on the nut.

Oy, what a mess, indeed. It appears the nut broke, or a plastic part came out of the center of it, and there's no way to tighten it down again. I can see how it would work though, if I hadn't fucked it up.

I just wrapped it all up like a mummy with the teflon tape. Gonna have to get a new nut tomorrow anyway, along with more teflon tape. Luckily, I was well prepared with plenty of towels, and the drip pan on my bed downstairs.

I suppose if I had never messed with this stuff in the first place, none of this mess would have happened. It's just that when my roommate mentioned the noise, I thought "I haven't been crazy all these years, it really is loud."

And I never did anything about it before when my dad was here, because I figured it was his problem. But I have to remind myself every once in a while that my dad is an idiot.

So my next question is: What's the harm in running the system at low pressure? Is it inefficient? It's probably been running at low pressure for a long time, and the temperature has been bearable. (Also, I used to live upstairs, and it was always warmer up there; due to heat rising, and probably good insulation. Noisy, though.)

Yeah, all the valves downstairs are immovable, it appears since the radiators were painted gods-know-when. They seem to be working fine though. I better not touch them. :shotgun:

Thanks (again and again) Bruce.

Besides being inefficient you'll probably shorten the life of the circulating pump considerably, running low pressure. The higher the pressure (within reason) the less chance of cavitating the pump, creating a large boundry layer in the system and better heat transfer.
Oh, and higher pressure makes leaks show up reeeaaal goooood.:D