Hi jjustinia,

Does your prv look like one of these?(pics at bottom)
The lever just releases the spring allowing water to fill the system faster. So yes this is an option to bleed system faster, just be careful not to let pressure get over thirty pounds as stated earlier. But the system should fill by itself without pulling the lever. Your prv may be plugged or worn out. Do you have a pressure gausge on or near the boiler? Also, I'm assuming you have the large cast iron radiators. They hold a lot of water and may take quite some time to completely fill(bleed) if they were all completely drained.

The pumps running will not affect bleeding, but it won't help it either. (however once system is bled to point of getting water out of all bleeders, then it does help to turn pumps on and bleed again. This is because once you have the system mostly bled, the pumps will help any trapped air in the lines move up to the bleeders at the registers.) This is why it is important to turn heat on(pumps circulating) and bleed system again once initial bleeding is done.

Now, about the prv not supplying enough pressure to bleed top story registers. This is actually a valid concern. Like I said, a prv is factory set to 12psi. If you have registers that are say thirty feet above the boiler(prv) then you will be getting little to no water at that point. Let me explain. Every ten feet high you go, you lose 4.14 psi. We will just call it 4psi to simplify. So at thirty feet high, you will get no pressure. For this senario, the release lever on the prv comes in mighy handy for bleeding. Also, if this is your case, you may have to adjust the prv up to say 18, 20, 22 psi at gauge reading on boiler. Just very important to keep an eye on gauge and make sure it does not go beyond 30psi when boiler heats up to shut off point(normally 180 to 190 degrees f.)

Sounds like you've got a pretty good handle on the bleeding. Give er a go and let us know how things work out. Lee.

Ps. Bob is giving great advice, and is correct about the way we usually try to answer questions. I may be getting a little more involved in my answers than I should, but I've just seen to many times when I go to work on a boiler, one thing leads to the next. Most common hot water boiler problems,, air in the lines, bad expansion tank, bad or plugged press reducing valve(very, very common), bad circulation pump. There are many other things that can and do go wrong with boilers, but I've found these to be most common.

Thank you very much, that is the prv that I have. In addition, everything you say makes sense and is exactly the kind of guidance I was looking for. I have a two-story house, so I have a better understanding why I may not get a full bleed before putting on pumps, as has happened in the past.

I prefer a more in depth answer for exactly the reason you describe. No project ever goes exactly as you expect or like the instruction books or videos explain. I like to have more knowledge so I can troubleshoot when something goes wrong. For example, I fully expect that my second floor radiators will not spurt water during the bleed until I get to the point that I turn on the pumps. Now, thanks to your answer, I know why and how to handle this, as opposed to just sitting there for hours waiting for water that won't come until I get to the point that I turn on the pumps. Of course I won't turn them on until aftert fully filling the system and bleeding as much as I can first. I know that when dealing with a boiler you obviously do not want to blow yourself up with too much pressure and that is why I appreciate your advice about using the prv lever sparingly to help speed things up, even though I know there is a pressure relief vavle, I want to know where the danger zone is, so I can make sure I don't put myself there.

I hear what both of you are saying about the advice you are try to give. I was looking for more in depth info specific to what I was asking. I was hoping to show the level of knowledge I already had by describing what I knew so you could see what I was leaving out. If I was not clear, I appologize. MGD- Thank you for responding directly to the questions I had in my posts!

I will tackle this in a few days. I have few projects going on at the same time.

I go the system up and running, thanks for your help. I did run into a couple of issues. One radiator on the first floor bleeds water with very little pressure, as compared to the others. It gets hot fine but I was worried there may be something cloged in the bleeder. This is the same radiator I removed so I am focusing on it to make sure it is running correctly. On another radiator the bleeder is stripped, the screw that you loosen to bleed has it flat head slot carved out and I can't get a grip on it. It is not the hex or square kind. It is a screw with a flat head slot. They are very small like 1/4 inch bleeder valves. Not sure what to do. It is as simple as taking a wrench to the entire valve and unscrewing it and then screwing in another? It can't bleed it now and it is the one in my living room.

Yep, remove complete bleeder and install a new one, of course this means taking the pressure off the system again. No need to drain complete system, just take the pressure off, have the new bleeder ready to go(tefloned or pipe doped) and switch them out as fast as you can. Have some towels handy for any water that does spill. While you have the pressure of the system, I would replace the slow bleeder also. Take a close look at the port that the bleeder screws into, as it may be partially plugged, if it is, clean it out with a small pocket knife or any thing that will fit into the hole. Remember, doing this as quickly as possible with towels to catch any residual water will keep you from having to bleed entire system again.

Thanks for the update. Please let us know how it goes. Lee.

OK, I got the new bleeder installed, but the air holes are pointing out horizontally. Not the biggest deal. They stopped turning in the up position and I forced them down a little further. I feel if I put more pressure on them to turn them into the down positoin, it will strip the thread. They both work fine and both problems have been fixed and I am back up and running. But is there something that I should have done to get them facing down properly?

Really doesn't matter which way the bleeder faces, only reason down is nice is it is easier to catch the water when bleeding. Only way to get the bleeder exactly where you want it is to use a lot of teflon tape, this way you don't have to tighten it quite as much, so you can stop when vent is down when it gets fairly tight. Glad to hear everything has worked out well for you. Good job. Now sit back and enjoy the heat. Take care. Lee.