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Author Bleeding a Boiler
Mike

2005-06-16, 2:27 pm

What is the proper way to bleed a hot water boiler w/radiators? Is it
normal for the system to use water if there are no leaks?


Mike Grooms

2005-06-16, 2:27 pm


"Mike"

Water has dissolved air in it that bubbles out and gets trapped in
radiators, not allowing the hot water to flow fully. Each radiator should
have a little bleeder at the top that operates with a little wrench or
screwdriver. These bleeders might also be at high points of the piping
where the pipe goes up and then down. Repeated bleeding is needed till all
the air is eliminated. Since a boiler uses the same water over and over,
eventually, all the free air gets eliminated.

If your system is typical, then, no it shouldn't use much fresh water.
Maybe the relief valve is leaking, or blowing off for some reason, but when
fresh water is introduced into the system, with it comes more dissolved air.
Then the bleeding must take place again and again.

Again, if your system is typical, the pressure gauge should read about 14
psi. If it's much greater, then the automatic fill valve is faulty. The
temperature is a harder call, since systems vary so much, but if it's more
than 200 degrees, there's probably a problem. You might also simply have a
leak in the piping that's undetected.



Mike

2005-06-16, 2:27 pm

I continue to have to bleed the system. I do realize introducing new water
brings air, so I must install some auto bleeders. Where do you recommend
them going? I get a bang after the circulator pump turns on after approx. 10
seconds. The bang seems to be coming from the closest radiator to the
boiler. Today I noticed the system pressure dropped to 11 psi.. The
climate is a little milder lately and the boiler has run less. I don't know
if I am only watching it more because of the bang or if the psi has done
this in the past. But I always thought it stayed at 14 psi. Temp set at
180*F. I also thought the accu-stat may have been at fault so I turned it
up to test for the heck and when set at 220*F it boils near 212*F which
would be correct.
How do you determine how full the steel non-bladder tank is filled?
Thank You, Mike

"Mike Grooms" <ironmike@fuse.net> wrote in message
news:%Ye0e.31$Hj1.7@fe37.usenetserver.com...
quote:

>
> "Mike"
>
> Water has dissolved air in it that bubbles out and gets trapped in
> radiators, not allowing the hot water to flow fully. Each radiator should
> have a little bleeder at the top that operates with a little wrench or
> screwdriver. These bleeders might also be at high points of the piping
> where the pipe goes up and then down. Repeated bleeding is needed till all
> the air is eliminated. Since a boiler uses the same water over and over,
> eventually, all the free air gets eliminated.
>
> If your system is typical, then, no it shouldn't use much fresh water.
> Maybe the relief valve is leaking, or blowing off for some reason, but

when
quote:

> fresh water is introduced into the system, with it comes more dissolved

air.
quote:

> Then the bleeding must take place again and again.
>
> Again, if your system is typical, the pressure gauge should read about

14
quote:

> psi. If it's much greater, then the automatic fill valve is faulty. The
> temperature is a harder call, since systems vary so much, but if it's more
> than 200 degrees, there's probably a problem. You might also simply have

a
quote:

> leak in the piping that's undetected.
>
>
>



Mike Grooms

2005-06-16, 2:27 pm


"Mike"

If your expansion tank is waterlogged, the pressure relief valve will run
every time the boiler kicks in. Can you see where the relief valve drains?

The automatic bleeders are usually placed near the boiler, on a high area
of the main feed line.



Mike

2005-06-16, 2:27 pm

The relief valve drains to the side of the boiler to a drain (dry, no relief
opening)
Automatic Bleeder: main feed to radiators or the auto fill line?
Tx, mike

"Mike Grooms" <ironmike@fuse.net> wrote in message
news:Hdq0e.1958$Hj1.301@fe37.usenetserver.com...
quote:

>
> "Mike"
>
> If your expansion tank is waterlogged, the pressure relief valve will

run
quote:

> every time the boiler kicks in. Can you see where the relief valve

drains?
quote:

>
> The automatic bleeders are usually placed near the boiler, on a high

area
quote:

> of the main feed line.
>
>
>



Mike Grooms

2005-06-16, 2:27 pm


"Mike"

The feed to the radiators, or on the high pipe that goes to the expansion
tank.



Mark Monson

2005-06-16, 2:27 pm

If you have the non bladder type of expansion tank, you should not be using
automatic bleeders. If you have problems with air in the radiators it is likely
from low pressure, not using a boiler fitting on the boiler, not using an ATF on the
tank, or not properly piping the tank to the boiler. You have to continuously
separate and return air to the expansion tank or you will get air bound in the
radiators and water logged in the expansion tank.

MM

"Mike" <mike912@comcast.net> wrote in message
news:tK-dnQ0CQMtzGt_fRVn-tQ@comcast.com...
quote:

> The relief valve drains to the side of the boiler to a drain (dry, no relief
> opening)
> Automatic Bleeder: main feed to radiators or the auto fill line?
> Tx, mike
>
> "Mike Grooms" <ironmike@fuse.net> wrote in message
> news:Hdq0e.1958$Hj1.301@fe37.usenetserver.com...
> run
> drains?
> area
>
>



Mike

2005-06-16, 2:27 pm

You have to continuously
separate and return air to the expansion tank or you will get air bound in
the
radiators and water logged in the expansion tank.

How do you accomplish this separation?

"Mark Monson" <m_monson@ztech.com> wrote in message
news:eAF0e.52526$6g7.13369@bignews1.bellsouth.net...
quote:

> If you have the non bladder type of expansion tank, you should not be

using
quote:

> automatic bleeders. If you have problems with air in the radiators it is

likely
quote:

> from low pressure, not using a boiler fitting on the boiler, not using an

ATF on the
quote:

> tank, or not properly piping the tank to the boiler. You have to

continuously
quote:

> separate and return air to the expansion tank or you will get air bound in

the
quote:

> radiators and water logged in the expansion tank.
>
> MM
>
> "Mike" <mike912@comcast.net> wrote in message
> news:tK-dnQ0CQMtzGt_fRVn-tQ@comcast.com...
relief[vbcol=seagreen]
will[vbcol=seagreen]
high[vbcol=seagreen]
>
>



Mark Monson

2005-06-16, 2:27 pm


"Mike" <mike912@comcast.net> wrote in message
news:soKdnUZR-ufSy97fRVn-oQ@comcast.com...
quote:

> You have to continuously
> separate and return air to the expansion tank or you will get air bound in
> the
> radiators and water logged in the expansion tank.
>
> How do you accomplish this separation?


Call a plumber or hydronic heating tech. You want something to putter around with,
get a model train kit. A boiler can be a bomb - not something for the unqualified
to goof around with.

MM

quote:

>
> "Mark Monson" <m_monson@ztech.com> wrote in message
> news:eAF0e.52526$6g7.13369@bignews1.bellsouth.net...
> using
> likely
> ATF on the
> continuously
> the
> relief
> will
> high
>
>



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