# Bleeding the Air out of boiler without bleeder valves



## Clutchcargo (Mar 31, 2007)

I had the same problem last year when I installed baseboard in series. Turn the water on and let it run for 30-45 minutes. It seems like a long time but that was the only way I could get all the air out of my system.


Edit: 
You're pictures are a little small to tell if you are hooked up the the correct spigot. You shouldn't run the heater to bleed it. You have to run the water full tilt through the system, not just a trickle and again, don't fire the unit while you do this.


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## beetlebabs (Jul 22, 2007)

Thanks Clutchcargo

I had been told before to run the system cold, and so i turned the gas feed off before i turned my thermostat up. However, I found that the pump would not start up until I turned the gas back on and so i had to run it hot. Maybe there is another way to run it cold?


I have tried to fix this problem about 6 or 7 times now. Each time I turn the system on full blast and I have let it run for up to 3 hours before I give up. While running full tilt I control the _drain valve_ by opening and closing it. If I leave it mostly open or mostly closed air doesn't come out as much as if I alternate between open and closed - but always while the system is running full blast. When you say turn the water on do you mean the drain valve? You left it fully open for 45 minutes?


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## redline (Mar 5, 2006)

beetlebabs said:


> We bled the system in order to remove a baseboard radiator during our kitchen renovations.


If you were able to disconnect the radiator for the kitchen reno then it may be in your best interest to install a bleeder.


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## Clutchcargo (Mar 31, 2007)

beetlebabs said:


> Thanks Clutchcargo
> 
> I had been told before to run the system cold, and so i turned the gas feed off before i turned my thermostat up. However, I found that the pump would not start up until I turned the gas back on and so i had to run it hot. Maybe there is another way to run it cold?


The pump doesn't need to run to bleed the system. There should be a valve that isolates the zone, in my system I need to close the valve to make sure the water flows through the registers and then to the drain spigot. If the valve is left open, the water flow only goes through the boiler and down the drain and doesn't bleed the system at all. 

I tried running the water through my system for a just a few minutes with no results, finally, I just opened it up and walked away.


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## beetlebabs (Jul 22, 2007)

Makes sense, but I don't know what this valve looks like or how to find it. Our apartment is small and has only one thermostat, therefore I believe only one zone.


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## redline (Mar 5, 2006)

If it is just one zone then it may not have a zone valve.

Can you post more photos of the pipes around the boiler?

A zone valve will usually have wires come from it.


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## MechanicalDVR (Jul 4, 2007)

In order to get the air out of the loop in theory, you need to isolate the pump inlet from the system (close valve between pump and boiler) and drain water from return piping with new water being fed in from supply piping. Post some better pictures for further info.


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## beetlebabs (Jul 22, 2007)

*Resolved!*

Thanks everyone for your help. We fixed it last night using the following techniques:
- increased pressure in the system using the pressure regulator on top of boiler
- ran the system cold 
- hooked the hose up to return spigot and then closed the return valve underneath, so water was feeding through the system at about 30psi and leaving at our hose, thus closing the continuous loop. As soon as we did that tons of air and filthy water erupted out of the hose.

It Worked! Thanks!


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## mstoneroses (Dec 12, 2007)

I have the 3rd line on my apt which is not getting that much heat . I am a newbie in bleeding air out of the system. Ive read several of the relpies and getting the idea of more or less how boilers work. My questions are what should be the pressure on the system before i can start bleeding air out of the system. I tried it last night by putting it at 30 before opening the valves and noticed lots of air coming out. I did it for a hour but it seems that Im still having the same problem - not that much heat on the attic. Why does this process has to be done in cold water? What is the proper psi and temperature ? Am I doing the bleeding right by opening the valve above the hose while the valve under the hose is closed? Thanks.


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