You probably don't have enough pressure in your boiler. Check your pressure
gauge to see how much you have. Every pound of pressure is equal to 2.31
feet. So if your highest radiators are 30 feet above the boiler then you
would need at least 13 pounds of pressure at the boiler just to raise the
water that high.
----- Original Message -----
From:
Newsgroups: alt.home.repair
Sent: Saturday, January 01, 2005 8:55 PM
Subject: bleeding radiators


i start from the top floor working my way down to the second. 3 out of
5 upstairs are really hot but i get neither air or water from them.
other 2 are luke warm - get some air but when air stops i get no water.

moving to main floor i get air from all 3 and are working fine. when
the air stops i should get water flow from the valve(?). any ideas on
this?

On Sun, 02 Jan 2005 12:19:27 GMT, "Tom Ingle"
wrote:

You probably don't have enough pressure in your boiler. Check your pressure
gauge to see how much you have. Every pound of pressure is equal to 2.31
feet. So if your highest radiators are 30 feet above the boiler then you
would need at least 13 pounds of pressure at the boiler just to raise the
water that high.

While I agree with the above, I would add a couple points:

1. It is always a good idea to have a little extra pressure, so I
recommend measuring the height of the system and dividing by 2. For a
30 foot system, I recommend setting the minimum pressure at 15 psi.

2. When the boiler is heating, the water expands, increasing the
pressure. This extra pressure from expansion must be removed before
measuring and adjusting the pressure. This can be accomplished by
turning off the boiler and pump, then draining off water from the
boiler until cold fill water starts feeding into the system. Close the
boiler drain and wait. When the water stops feeding into the system,
this is your minimum pressure.

Adjust if needed, then turn everything back on and bleed the system
starting at the top.

If you do it right, you will probably never have to bleed the system
again.

_______________

Gary R. Lloyd CMS
HVACR Troubleshooting Books/Software
Written by a veteran Service Technician

https://www.merchantamerica.com/tmethod/

On Sun, 02 Jan 2005 12:50:27 GMT, (Gary R. Lloyd)
wrote:

On Sun, 02 Jan 2005 12:19:27 GMT, "Tom Ingle"
wrote:

You probably don't have enough pressure in your boiler. Check your pressure
gauge to see how much you have. Every pound of pressure is equal to 2.31
feet. So if your highest radiators are 30 feet above the boiler then you
would need at least 13 pounds of pressure at the boiler just to raise the
water that high.

While I agree with the above, I would add a couple points:

1. It is always a good idea to have a little extra pressure, so I
recommend measuring the height of the system and dividing by 2. For a
30 foot system, I recommend setting the minimum pressure at 15 psi.

2. When the boiler is heating, the water expands, increasing the
pressure. This extra pressure from expansion must be removed before
measuring and adjusting the pressure. This can be accomplished by
turning off the boiler and pump, then draining off water from the
boiler until cold fill water starts feeding into the system. Close the
boiler drain and wait. When the water stops feeding into the system,
this is your minimum pressure.


Why does the pressure increase and water expand if you have a properly
opreating expansion tank?

Adjust if needed, then turn everything back on and bleed the system
starting at the top.

Bleed the system starting at the top????????
Nope. Never

If you do it right, you will probably never have to bleed the system
again.

In theory, maybe, but not in the real world.
Maybe we are on 2 different "pages" here?
Fill me in.....
Bubba


_______________

Gary R. Lloyd CMS
HVACR Troubleshooting Books/Software
Written by a veteran Service Technician

https://www.merchantamerica.com/tmethod/

Hi Doug, hope you are having a nice day

On 02-Jan-05 At About 09:19:15, Doug Miller wrote to All
Subject: Bleeding radiators

DM From: (Doug Miller)

DM In article jFRBd.10922$wu4.9627@attbi_s52, "Tom Ingle"
DM wrote You probably don't have enough pressure
DM in your boiler. Check your pressure gauge to see how much you have.
DM Every pound of pressure is equal to 2.31 feet. So if your highest
DM radiators are 30 feet above the boiler then you
DM would need at least 13 pounds of pressure at the boiler just to
DM raise the water that high.

DM Ummmm.... isn't that what the circulating pumps are for?

Nope, "circulators" are for "circulating" the water. they aren't designed to
act as lift pumps.


-= HvacTech2 =-


... "Hermits have no peer pressure." - s.w.

___ TagDude 0.92á+[DM]
++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++
spam protection measure, Please remove the 33 to send e-mail

In article jFRBd.10922$wu4.9627@attbi_s52, "Tom Ingle" wrote:
You probably don't have enough pressure in your boiler. Check your pressure
gauge to see how much you have. Every pound of pressure is equal to 2.31
feet. So if your highest radiators are 30 feet above the boiler then you
would need at least 13 pounds of pressure at the boiler just to raise the
water that high.

Ummmm.... isn't that what the circulating pumps are for?

i start from the top floor working my way down to the second. 3 out of
5 upstairs are really hot but i get neither air or water from them.
other 2 are luke warm - get some air but when air stops i get no water.

moving to main floor i get air from all 3 and are working fine. when
the air stops i should get water flow from the valve(?). any ideas on
this?

I imagine you're bleeding while the circulating pumps are not running. Try it
when they are.

Since air moves upward, you should bleed the *lowest* radiators first. If you
start at the top, you may have to go back and bleed the upper ones again after
the air lower in the system finds its way up to the top.

On Sun, 02 Jan 2005 13:22:40 GMT, Bubba
wrote:

On Sun, 02 Jan 2005 12:50:27 GMT, (Gary R. Lloyd)
wrote:

On Sun, 02 Jan 2005 12:19:27 GMT, "Tom Ingle"
wrote:

You probably don't have enough pressure in your boiler. Check your pressure
gauge to see how much you have. Every pound of pressure is equal to 2.31
feet. So if your highest radiators are 30 feet above the boiler then you
would need at least 13 pounds of pressure at the boiler just to raise the
water that high.

While I agree with the above, I would add a couple points:

1. It is always a good idea to have a little extra pressure, so I
recommend measuring the height of the system and dividing by 2. For a
30 foot system, I recommend setting the minimum pressure at 15 psi.

2. When the boiler is heating, the water expands, increasing the
pressure. This extra pressure from expansion must be removed before
measuring and adjusting the pressure. This can be accomplished by
turning off the boiler and pump, then draining off water from the
boiler until cold fill water starts feeding into the system. Close the
boiler drain and wait. When the water stops feeding into the system,
this is your minimum pressure.


Why does the pressure increase and water expand if you have a properly
opreating expansion tank?

Water always expands when heated. That's just basic physics.

Without the expansion tank, the pressure would rise very rapidly
because water cannot be compressed. With the expansion tank, the
expanded water pushes up into the tank, compressing the air.

The pressure of both the water and the air are increased as a result
of that compression. How much the pressure increases depends upon the
amount of expansion and the size of the tank. There is always some
increase in pressure.

Adjust if needed, then turn everything back on and bleed the system
starting at the top.

Bleed the system starting at the top????????
Nope. Never

Why not?

If you do it right, you will probably never have to bleed the system
again.

In theory, maybe, but not in the real world.
Maybe we are on 2 different "pages" here?
Fill me in.....
Bubba

Generally there is some sort of automatic vent for the very tiny
amount of air entering the system with the fill water. Usually, if a
system needs repeat bleeding it is because there is insufficient fill
pressure, resulting in a vacuum at the top of the system whenever the
boiler is cold.

Note: When the water is pumped into the boiler rather than away from
the boiler, there may (or may not) be a vacuum at the suction side of
the pump, in which case additional fill pressure may be needed.

_______________

Gary R. Lloyd CMS
HVACR Troubleshooting Books/Software
Written by a veteran Service Technician

https://www.merchantamerica.com/tmethod/

On Sun, 02 Jan 2005 14:19:15 GMT, (Doug Miller)
wrote:

In article jFRBd.10922$wu4.9627@attbi_s52, "Tom Ingle" wrote:
You probably don't have enough pressure in your boiler. Check your pressure
gauge to see how much you have. Every pound of pressure is equal to 2.31
feet. So if your highest radiators are 30 feet above the boiler then you
would need at least 13 pounds of pressure at the boiler just to raise the
water that high.

Ummmm.... isn't that what the circulating pumps are for?

Nope, they are for circulating water in a full system. The pressure is
increased on the discharge side and decreased on the suction side. At
the midpoint of each loop, the effects cancel each other out.

And, if the pump suction is in a vacuum, it will suck air past the
seal. It is also in danger of cavitating, which can destroy the pump.

_______________

Gary R. Lloyd CMS
HVACR Troubleshooting Books/Software
Written by a veteran Service Technician

https://www.merchantamerica.com/tmethod/

On Sun, 02 Jan 2005 14:37:28 GMT, (Gary R. Lloyd)
wrote:

On Sun, 02 Jan 2005 13:22:40 GMT, Bubba
wrote:

On Sun, 02 Jan 2005 12:50:27 GMT, (Gary R. Lloyd)
wrote:

On Sun, 02 Jan 2005 12:19:27 GMT, "Tom Ingle"
wrote:

You probably don't have enough pressure in your boiler. Check your pressure
gauge to see how much you have. Every pound of pressure is equal to 2.31
feet. So if your highest radiators are 30 feet above the boiler then you
would need at least 13 pounds of pressure at the boiler just to raise the
water that high.

While I agree with the above, I would add a couple points:

1. It is always a good idea to have a little extra pressure, so I
recommend measuring the height of the system and dividing by 2. For a
30 foot system, I recommend setting the minimum pressure at 15 psi.

2. When the boiler is heating, the water expands, increasing the
pressure. This extra pressure from expansion must be removed before
measuring and adjusting the pressure. This can be accomplished by
turning off the boiler and pump, then draining off water from the
boiler until cold fill water starts feeding into the system. Close the
boiler drain and wait. When the water stops feeding into the system,
this is your minimum pressure.


Why does the pressure increase and water expand if you have a properly
opreating expansion tank?

Water always expands when heated. That's just basic physics.

Without the expansion tank, the pressure would rise very rapidly
because water cannot be compressed. With the expansion tank, the
expanded water pushes up into the tank, compressing the air.

The pressure of both the water and the air are increased as a result
of that compression. How much the pressure increases depends upon the
amount of expansion and the size of the tank. There is always some
increase in pressure.

Although, in theory, I would say there is an increase in pressure,
again I am applying this to the everyday world and the everyday
residential boiler. I do a lot of boilers and repairs. The boiler
pressure gauge rarely moves during burner operation unless the
expansion tank is water logged.


Adjust if needed, then turn everything back on and bleed the system
starting at the top.

Bleed the system starting at the top????????
Nope. Never

Why not?


Why not, you ask? Im guessing you are just playin with me but I'll
bite. My answer would be because if I start purging a system of air
from the 2nd or 3rd floor and then work my way down to the first floor
or even the basement, I am almost guaranteed that I will still have
air in a 2nd or 3rd floor radiator. Im assuming you know that air is
lighter than water :-) and that the air will make its way to the top
floors while the water is constantly trying to settle down lower due
to gravity? Now, although I like your thinking about purging air from
the top down, I DONT believe my customers would like me to repeatedly
purge the air from the system incorrectly at $150 hr! I would believe
that they would like me to do it correctly and quickly the first time.

If you do it right, you will probably never have to bleed the system
again.

In theory, maybe, but not in the real world.
Maybe we are on 2 different "pages" here?
Fill me in.....
Bubba

Generally there is some sort of automatic vent for the very tiny
amount of air entering the system with the fill water. Usually, if a
system needs repeat bleeding it is because there is insufficient fill
pressure, resulting in a vacuum at the top of the system whenever the
boiler is cold.

and many times there is not an auto vent. Hell, I even see tons of
systems where someone was too stupid, too lazy or too cheap to install
valves on both sides of the circulator, fill valve and boiler! Those
valves save tremendous amounts of time and money in future repairs.
Bubba

Note: When the water is pumped into the boiler rather than away from
the boiler, there may (or may not) be a vacuum at the suction side of
the pump, in which case additional fill pressure may be needed.

_______________

Gary R. Lloyd CMS
HVACR Troubleshooting Books/Software
Written by a veteran Service Technician

https://www.merchantamerica.com/tmethod/

On Sun, 02 Jan 2005 17:47:24 GMT, Bubba
wrote:

On Sun, 02 Jan 2005 14:37:28 GMT, (Gary R. Lloyd)
wrote:

On Sun, 02 Jan 2005 13:22:40 GMT, Bubba
wrote:

On Sun, 02 Jan 2005 12:50:27 GMT, (Gary R. Lloyd)
wrote:

On Sun, 02 Jan 2005 12:19:27 GMT, "Tom Ingle"
wrote:

You probably don't have enough pressure in your boiler. Check your pressure
gauge to see how much you have. Every pound of pressure is equal to 2.31
feet. So if your highest radiators are 30 feet above the boiler then you
would need at least 13 pounds of pressure at the boiler just to raise the
water that high.

While I agree with the above, I would add a couple points:

1. It is always a good idea to have a little extra pressure, so I
recommend measuring the height of the system and dividing by 2. For a
30 foot system, I recommend setting the minimum pressure at 15 psi.

2. When the boiler is heating, the water expands, increasing the
pressure. This extra pressure from expansion must be removed before
measuring and adjusting the pressure. This can be accomplished by
turning off the boiler and pump, then draining off water from the
boiler until cold fill water starts feeding into the system. Close the
boiler drain and wait. When the water stops feeding into the system,
this is your minimum pressure.


Why does the pressure increase and water expand if you have a properly
opreating expansion tank?

Water always expands when heated. That's just basic physics.

Without the expansion tank, the pressure would rise very rapidly
because water cannot be compressed. With the expansion tank, the
expanded water pushes up into the tank, compressing the air.

The pressure of both the water and the air are increased as a result
of that compression. How much the pressure increases depends upon the
amount of expansion and the size of the tank. There is always some
increase in pressure.

Although, in theory, I would say there is an increase in pressure,
again I am applying this to the everyday world and the everyday
residential boiler. I do a lot of boilers and repairs. The boiler
pressure gauge rarely moves during burner operation unless the
expansion tank is water logged.

The largest increase in pressure would be in going from a cold boiler
to full temperature. Once it is up to temperature, the normal
operation will cause little movement in pressure because there is
little movement in temperature and the pressure is already elevated.
It is when the boiler is off for an extended period that air is most
likely to enter the system as a result of insufficient cold fill
pressure. In any case, expansion pressure needs to be removed in order
to get the fill pressure right.

Adjust if needed, then turn everything back on and bleed the system
starting at the top.

Bleed the system starting at the top????????
Nope. Never

Why not?


Why not, you ask? Im guessing you are just playin with me but I'll
bite. My answer would be because if I start purging a system of air
from the 2nd or 3rd floor and then work my way down to the first floor
or even the basement, I am almost guaranteed that I will still have
air in a 2nd or 3rd floor radiator. Im assuming you know that air is
lighter than water :-) and that the air will make its way to the top
floors while the water is constantly trying to settle down lower due
to gravity? Now, although I like your thinking about purging air from
the top down, I DONT believe my customers would like me to repeatedly
purge the air from the system incorrectly at $150 hr! I would believe
that they would like me to do it correctly and quickly the first time.

Okay, I'll buy that, based on your experience. I have not worked on
any residential systems for several decades, and don't recall ever
working on a residential boiler. Commercial boilers have such things
as automatic vents at the tops of the risers. I have always vented
from the top down without having any problems, but I accept that
residential systems are not the same.

If you do it right, you will probably never have to bleed the system
again.

In theory, maybe, but not in the real world.
Maybe we are on 2 different "pages" here?
Fill me in.....
Bubba

Generally there is some sort of automatic vent for the very tiny
amount of air entering the system with the fill water. Usually, if a
system needs repeat bleeding it is because there is insufficient fill
pressure, resulting in a vacuum at the top of the system whenever the
boiler is cold.

and many times there is not an auto vent. Hell, I even see tons of
systems where someone was too stupid, too lazy or too cheap to install
valves on both sides of the circulator, fill valve and boiler! Those
valves save tremendous amounts of time and money in future repairs.
Bubba

Note: When the water is pumped into the boiler rather than away from
the boiler, there may (or may not) be a vacuum at the suction side of
the pump, in which case additional fill pressure may be needed.

_______________

Gary R. Lloyd CMS
HVACR Troubleshooting Books/Software
Written by a veteran Service Technician

https://www.merchantamerica.com/tmethod/


_______________

Gary R. Lloyd CMS
HVACR Troubleshooting Books/Software
Written by a veteran Service Technician

https://www.merchantamerica.com/tmethod/

On Sun, 02 Jan 2005 18:28:10 GMT, (Gary R. Lloyd)
wrote:

On Sun, 02 Jan 2005 17:47:24 GMT, Bubba
wrote:

On Sun, 02 Jan 2005 14:37:28 GMT, (Gary R. Lloyd)
wrote:

On Sun, 02 Jan 2005 13:22:40 GMT, Bubba
wrote:

On Sun, 02 Jan 2005 12:50:27 GMT, (Gary R. Lloyd)
wrote:

On Sun, 02 Jan 2005 12:19:27 GMT, "Tom Ingle"
wrote:

You probably don't have enough pressure in your boiler. Check your pressure
gauge to see how much you have. Every pound of pressure is equal to 2.31
feet. So if your highest radiators are 30 feet above the boiler then you
would need at least 13 pounds of pressure at the boiler just to raise the
water that high.

While I agree with the above, I would add a couple points:

1. It is always a good idea to have a little extra pressure, so I
recommend measuring the height of the system and dividing by 2. For a
30 foot system, I recommend setting the minimum pressure at 15 psi.

2. When the boiler is heating, the water expands, increasing the
pressure. This extra pressure from expansion must be removed before
measuring and adjusting the pressure. This can be accomplished by
turning off the boiler and pump, then draining off water from the
boiler until cold fill water starts feeding into the system. Close the
boiler drain and wait. When the water stops feeding into the system,
this is your minimum pressure.


Why does the pressure increase and water expand if you have a properly
opreating expansion tank?

Water always expands when heated. That's just basic physics.

Without the expansion tank, the pressure would rise very rapidly
because water cannot be compressed. With the expansion tank, the
expanded water pushes up into the tank, compressing the air.

The pressure of both the water and the air are increased as a result
of that compression. How much the pressure increases depends upon the
amount of expansion and the size of the tank. There is always some
increase in pressure.

Although, in theory, I would say there is an increase in pressure,
again I am applying this to the everyday world and the everyday
residential boiler. I do a lot of boilers and repairs. The boiler
pressure gauge rarely moves during burner operation unless the
expansion tank is water logged.

The largest increase in pressure would be in going from a cold boiler
to full temperature. Once it is up to temperature, the normal
operation will cause little movement in pressure because there is
little movement in temperature and the pressure is already elevated.
It is when the boiler is off for an extended period that air is most
likely to enter the system as a result of insufficient cold fill
pressure. In any case, expansion pressure needs to be removed in order
to get the fill pressure right.

Adjust if needed, then turn everything back on and bleed the system
starting at the top.

Bleed the system starting at the top????????
Nope. Never

Why not?


Why not, you ask? Im guessing you are just playin with me but I'll
bite. My answer would be because if I start purging a system of air
from the 2nd or 3rd floor and then work my way down to the first floor
or even the basement, I am almost guaranteed that I will still have
air in a 2nd or 3rd floor radiator. Im assuming you know that air is
lighter than water :-) and that the air will make its way to the top
floors while the water is constantly trying to settle down lower due
to gravity? Now, although I like your thinking about purging air from
the top down, I DONT believe my customers would like me to repeatedly
purge the air from the system incorrectly at $150 hr! I would believe
that they would like me to do it correctly and quickly the first time.

Okay, I'll buy that, based on your experience. I have not worked on
any residential systems for several decades, and don't recall ever
working on a residential boiler. Commercial boilers have such things
as automatic vents at the tops of the risers. I have always vented
from the top down without having any problems, but I accept that
residential systems are not the same.

Damn Gary, you were starting to scare me there. :-) I thought you and
I might be living on 2 different poles of the earth.........you know,
like South America where the toilet water flushes down the bowl in the
opposite direction as here in North America. I understand where your
coming from. With bigger commercial boilers and piping, a little air
isnt a huge problem. In residential though, a bubble of air 1/2" in
diameter is enough to stop a radiator (baseboard) from heating.
Bubba

If you do it right, you will probably never have to bleed the system
again.

In theory, maybe, but not in the real world.
Maybe we are on 2 different "pages" here?
Fill me in.....
Bubba

Generally there is some sort of automatic vent for the very tiny
amount of air entering the system with the fill water. Usually, if a
system needs repeat bleeding it is because there is insufficient fill
pressure, resulting in a vacuum at the top of the system whenever the
boiler is cold.

and many times there is not an auto vent. Hell, I even see tons of
systems where someone was too stupid, too lazy or too cheap to install
valves on both sides of the circulator, fill valve and boiler! Those
valves save tremendous amounts of time and money in future repairs.
Bubba

Note: When the water is pumped into the boiler rather than away from
the boiler, there may (or may not) be a vacuum at the suction side of
the pump, in which case additional fill pressure may be needed.

_______________

Gary R. Lloyd CMS
HVACR Troubleshooting Books/Software
Written by a veteran Service Technician

https://www.merchantamerica.com/tmethod/


_______________

Gary R. Lloyd CMS
HVACR Troubleshooting Books/Software
Written by a veteran Service Technician

https://www.merchantamerica.com/tmethod/

In article , Bubba wrote:

Okay, I'll buy that, based on your experience. I have not worked on
any residential systems for several decades, and don't recall ever
working on a residential boiler. Commercial boilers have such things
as automatic vents at the tops of the risers. I have always vented
from the top down without having any problems, but I accept that
residential systems are not the same.

Damn Gary, you were starting to scare me there. :-) I thought you and
I might be living on 2 different poles of the earth.........you know,
like South America where the toilet water flushes down the bowl in the
opposite direction as here in North America. I understand where your
coming from. With bigger commercial boilers and piping, a little air
isnt a huge problem. In residential though, a bubble of air 1/2" in
diameter is enough to stop a radiator (baseboard) from heating.
Bubba

You call those baseboard heaters radiators too? I've been picturing
the cast iron monsters that I have here. Also, do you use a single
riser for multiple radiators? On different floors even? Ewwwww...
Every radiator in my home has it's own riser ( 1" black iron pipe ).

--
"De inimico non loquaris sed cogites."

On 3 Jan 2005 07:05:15 GMT, Ed Clarke wrote:

In article , Bubba wrote:

Okay, I'll buy that, based on your experience. I have not worked on
any residential systems for several decades, and don't recall ever
working on a residential boiler. Commercial boilers have such things
as automatic vents at the tops of the risers. I have always vented
from the top down without having any problems, but I accept that
residential systems are not the same.

Damn Gary, you were starting to scare me there. :-) I thought you and
I might be living on 2 different poles of the earth.........you know,
like South America where the toilet water flushes down the bowl in the
opposite direction as here in North America. I understand where your
coming from. With bigger commercial boilers and piping, a little air
isnt a huge problem. In residential though, a bubble of air 1/2" in
diameter is enough to stop a radiator (baseboard) from heating.
Bubba

You call those baseboard heaters radiators too? I've been picturing
the cast iron monsters that I have here. Also, do you use a single
riser for multiple radiators? On different floors even? Ewwwww...
Every radiator in my home has it's own riser ( 1" black iron pipe ).

Baseboard radiation. There, that better?
Yes, single riser works bestes" , but Ive seen em all.
Bubba

it was the circulator pump. thanks for the help. it was covered under
my furnace maintainance warrenty.

wrote:
If your radiators are bleeding, there is most likely a dead body
under
them. Call the police immediately and report a murder in your home.
You will want those bodies removed quickly or the smell will drive
you
out.

radiators are bled from the inside using the valve. your attempt at
humor leads me to beleive your momma dropped you on the floor as an
infant.



On Sun, 02 Jan 2005 12:19:27 GMT, "Tom Ingle"
wrote:

You probably don't have enough pressure in your boiler. Check your
pressure
gauge to see how much you have. Every pound of pressure is equal to
2.31
feet. So if your highest radiators are 30 feet above the boiler then
you
would need at least 13 pounds of pressure at the boiler just to
raise the
water that high.
----- Original Message -----
From:
Newsgroups: alt.home.repair
Sent: Saturday, January 01, 2005 8:55 PM
Subject: bleeding radiators


i start from the top floor working my way down to the second. 3
out of
5 upstairs are really hot but i get neither air or water from
them.
other 2 are luke warm - get some air but when air stops i get no
water.

moving to main floor i get air from all 3 and are working fine.
when
the air stops i should get water flow from the valve(?). any ideas
on
this?