Air in Pipes? What is the proper way to purge.

Tom L.

Help!!!!! I have a 2 story house built in the early 60's that has a closed loop system. There are 4 heat zones. At the end of last heating season I lost heat in the house. The contractor told me to bleed the system starting on the top floor at the farthest room from the boiler and work my way back. Doing this resulted in a small amount air air being purged but no real heat gain. This heating season the same problem and I followed the previous instructions with no real change. I have spent about 4 days trying to purge the system with no real heat gain. One full afternoon was spent bleeding the air from the check valve at the boiler. When the air valve was full the return water flow slowed down until the valve was purged. At one point I thought the air was not being replaced with water. Yesterday another contractor told me the opposite procedure to purge air from the system. Start at the lowest floor and work my way up. How long does it take to purge? Starting in the basement I had heat in two rads and the other two had water but it was coming out cold. I moved to the main floor that has two heat zones and got one working moderately but when I bleed the air from the pipe there is no sign of water. I have been working in my perceived order of the flow ( I may be wrong). Should not water come out after the air is bled? All I hear is the sound of the pressure being released and then nothing and no water. The contractor last night told me the heating system did not have to be on to purge air. Should I open all bleed valves in a zone and turn up the heat, then close each one in sequence as the water starts to come out. (will this even happen?) As you can tell I am at a loss of what to do. Any help would be GREATLY appreciated!!! Thanking you in advance, Tom

Tom L.

Hi! Can someone help me with my questions??? It is getting later in the evening and getting colder. Am I on the right track or way off course?

c-rex

Are you maintaing 12psi at you gauge? Are you venting base board ends?
Ok, keep your pressure at 12psi, with the lowest zone on, all others closed, vent until you have no more air, turn the stat down, go to the next zone and repeat until all four zones are vented.
Purge systems, thru a seris of valves and hose bibs are a tad bit differant, and if this is what you've got, then do not fire the boiler until all loops have been purged.
Purging chases the air out by blowing the air and water thru to a drain, until a steady flow of water comes out of the drain valve or hose, doing this to a hot or firing boiler in never to be done.

Unknown

You need to get the water

pressure up around 25 lbs and then bleed each zone one at a time. This can be done by pulling the lever on the pressure reducing valve. This is located on the cold water line to the boiler which brings city water to the boiler. By increasing this pressure it will force the air out of each zone. Once all the air is out reset water pressure to 12 to 14 pounds. The truth is I would prefer you having a contractor do this for you. I am suprised that they are telling you what to do but have not offered to do it for you.

Have you gone to find a contractor on this site and entered your zip code? What is your location?

Tom L.

Hi Chuck! Thanks for your quick reply. I am in a real bind. I have tried everywhich way but loose. I just went through the whole system again at each rad and got little puffs of air from some of the bleeder valves on the rads but no water coming out. I did have some heat this morning but now it is gone again. I took the day off work and now it looks like it has been wasted. I will try your suggestiion of raising the thermostat on the bottom zone first and bleeding the valve at each rad but the temp is so low the other zones valves are opening on their own. I will let you know how this works out. Thanks, Tom

Tom L.

Hi Tim Thanks for your reply. I am barely at 10psi and it fluctuates but no higher than 10. my line to the city water is open to replenish the water but I don't seem to be having any luck. I live in St. Catharines Ontario, Canada.

Tom L.

Hi ! Forgot to tell you I am barely making 10psi. I am bleeding base board bleeder valves as well as the reservoire by the boiler. It is only a little brass cylinder avout 2" X 3" with a release valve in the top, looks like a tire valve.

Unknown

If you do not mind a long distance call

call me here in USA at 401-437-0557. I will try to walk you through how to bleed the system.

bluenose_9

purge

This problem just cost you a days worth of wages? Get the pressure up before you start venting, if you can't raise it I would get your contractor back.

Tom L.

Hi thanks for your advice. I just talked to Tim on the phone and he said the same thing. It sounds like more than just bleeding the system. I called the contractor at Tim's suggestion and he will be here tomorrow. He feels it is some pump that is not getting the pressure up to force the air out. Thanks again.

Tom L.

Thanks everyone for your help!!!!! I will let you know tomorrow how it turns out. In the meantime we will be bundled up for the night. Tom

Howard

air&water

Here in the burbs of Chicago, I see quite a few bad installations of piping from a remodel with the heating pipes zig-zagging up and down with lots of places for air to collect and stop the flow. Often there's no means of bleeding the high spots or of isolating the loop in question to purge it. This week I had to remove a 3/4" plug from a pipe to dislodge a fart in a pipe feeding an undercabinet convector. You have to get creative to overcome the installer's incompetence. Figure out what valves to close to blast water through the affected loop. Good Luck. Howard

Tom L.

Hi Guys! I want to thank Chuck, Howard and especially Tim who took the time to be concerned about my problem. I sure was frustrated. All of you provided great advice. Up until last year my heating system had never given me any problems so I guess I was due since it has been in since 1962. Tim was right that the pressure was far to low to push the water up through the pipes. The contractor today told my wife that someone had turned a valve off. I swear it wasn't me! Since I know very little about the system, I think that was obvious, I wasn't about to go turning off and on valves that I know nothing about. I think it was the contractor I had last year. When I called him two weeks ago, he said he was really busy and he would get back to me. I nver heard from him. Turns out good for me since the contractor I had today was excellent and I will definitely use him again. Right now I am running 12psi and before I was at about 4psi when I was getting little puffs of air out the valves. My wife told me today the air was really being forced through and out the pipes. It was a very cold night and now we are all toasty. Thank you all very much again. Hope you have a great Thanks Giving! (Although you guys do celebrate it at the wrong time of year, too close to Christmas):-) lol from way up north, Tom Laing