I need to ensure I've got all the air out of my closed pressurised
system in order to resolve/eliminate another issue. Pressure is
around 0.8bar when I start, down to about 0.5bar when I've finished
and I then repressurise.

The bleed screws are those little square ones at the back (not side)
of each radiator so when they squirt out they hit the wallpaper.

The property is a bungalow so all radiators at ground level but the
pipes go up and over via the attic.

Anyhow most of the radiators instantly let out a silent stream of
water.

A couple sputter, water comes out but with a sputtering sound and/or a
whistling sound and this is where I'm confused. It seems no matter
how much I let out (I'm talking cup fulls not gallons) they still seem
to sputter. They sputtered yesterday, today and I expect they will
tomorrow.

Is this air in the system or is it just the shape of the screw?

Am I correct in assuming that air cannot be introduced into the system
unless there is serious corrosion or the like going on?

How much oxygen am I reintroducing repressurising the system?

--
AnthonyL

On 07/11/17 10:29, AnthonyL wrote:
I need to ensure I've got all the air out of my closed pressurised
system in order to resolve/eliminate another issue. Pressure is
around 0.8bar when I start, down to about 0.5bar when I've finished
and I then repressurise.

The bleed screws are those little square ones at the back (not side)
of each radiator so when they squirt out they hit the wallpaper.

The property is a bungalow so all radiators at ground level but the
pipes go up and over via the attic.

I'm debugging a similar (and new) system - my pipe runs are tortuous out
of necessity (upstairs is a dormer, so pipes go:

Up from boiler

Down to north side rads.

Down to interlink pipe to south side.

Up to distribution pipework

Down to rads.


Needless to say, the south side has two cold rads on the ends of the
distribution leg.

Trouble was expected - so after seeing how naive pipework behaves
(better than expected to be honest) I'm getting the plumbers back to
insert bottle type auto vents in several key locations once I can
determined where specifically the air seemed to be getting trapped.

A thermal camera would be dead useful here - are those hireable?

Otherwise, we'll do it the old fashioned way by feeling the pipes for
the lukewarm (neither hot flow nor cold return) bits.


So probably the same for you - add some bleeders in the high bits,
especially the returns.


Anyhow most of the radiators instantly let out a silent stream of
water.

They would generally - the air locks are in the pipe above.


A couple sputter, water comes out but with a sputtering sound and/or a
whistling sound and this is where I'm confused. It seems no matter
how much I let out (I'm talking cup fulls not gallons) they still seem
to sputter. They sputtered yesterday, today and I expect they will
tomorrow.

Is this air in the system or is it just the shape of the screw?

Probably air - you'll find there are one or two rads that seem to catch
odd bubbles of air that the pump manages to shove down a pipe.

Am I correct in assuming that air cannot be introduced into the system
unless there is serious corrosion or the like going on?

Correct.


How much oxygen am I reintroducing repressurising the system?


It won't matter if you add inhibitor.

On 07/11/2017 10:29, AnthonyL wrote:
I need to ensure I've got all the air out of my closed pressurised
system in order to resolve/eliminate another issue. Pressure is
around 0.8bar when I start, down to about 0.5bar when I've finished
and I then repressurise.

The bleed screws are those little square ones at the back (not side)
of each radiator so when they squirt out they hit the wallpaper.

You don't own a towel?


The property is a bungalow so all radiators at ground level but the
pipes go up and over via the attic.

You can fit an automatic air vent up there.



Anyhow most of the radiators instantly let out a silent stream of
water.

A couple sputter, water comes out but with a sputtering sound and/or a
whistling sound and this is where I'm confused. It seems no matter
how much I let out (I'm talking cup fulls not gallons) they still seem
to sputter. They sputtered yesterday, today and I expect they will
tomorrow.


Is the radiator hot right up to the top?



Is this air in the system or is it just the shape of the screw?

Am I correct in assuming that air cannot be introduced into the system
unless there is serious corrosion or the like going on?

How much oxygen am I reintroducing repressurising the system?

Very little. Just the oxygen dissolved in the water.

In article ,
AnthonyL wrote:
A couple sputter, water comes out but with a sputtering sound and/or a
whistling sound and this is where I'm confused. It seems no matter
how much I let out (I'm talking cup fulls not gallons) they still seem
to sputter. They sputtered yesterday, today and I expect they will
tomorrow.

Is this air in the system or is it just the shape of the screw?

If there is air in a rad, the very top won't get as hot as the rest.

--
*Do infants enjoy infancy as much as adults enjoy adultery?

Dave Plowman London SW
To e-mail, change noise into sound.

Tim Watts submitted this idea :
A thermal camera would be dead useful here - are those hireable?

Not quite so convenient, but you can do it with an IR thermometer and
from a distance.

Otherwise, we'll do it the old fashioned way by feeling the pipes for the
lukewarm (neither hot flow nor cold return) bits.

Dave Plowman (News) explained :
If there is air in a rad, the very top won't get as hot as the rest.

More obvious, if the heating has quite recently fired up.

On 07/11/17 10:42, GB wrote:
On 07/11/2017 10:29, AnthonyL wrote:
I need to ensure I've got all the air out of my closed pressurised
system in order to resolve/eliminate another issue.Â* Pressure is
around 0.8bar when I start, down to about 0.5bar when I've finished
and I then repressurise.

The bleed screws are those little square ones at the back (not side)
of each radiator so when they squirt out they hit the wallpaper.

You don't own a towel?

Oh I forgot - small towell, rag, hanky, kitchen roll - all of these
should result in near zero spillage.

On 07/11/2017 10:29, AnthonyL wrote:
I need to ensure I've got all the air out of my closed pressurised
system in order to resolve/eliminate another issue. Pressure is
around 0.8bar when I start, down to about 0.5bar when I've finished
and I then repressurise.

The bleed screws are those little square ones at the back (not side)
of each radiator so when they squirt out they hit the wallpaper.

The property is a bungalow so all radiators at ground level but the
pipes go up and over via the attic.

Anyhow most of the radiators instantly let out a silent stream of
water.

A couple sputter, water comes out but with a sputtering sound and/or a
whistling sound and this is where I'm confused. It seems no matter
how much I let out (I'm talking cup fulls not gallons) they still seem
to sputter. They sputtered yesterday, today and I expect they will
tomorrow.

Usually you find that any air in a system will mostly gravitate to one
or perhaps two radiators that are the highest in the system. The tops
will be noticeably cooler when the rest of it is hot if air is there.

If there is a lot of air in a poorly designed system after refilling
then you will hear it bubbling up in any vertical pipe runs and a change
in pump noise when there is air going through it.

Is this air in the system or is it just the shape of the screw?

If it sputters it is probably from gasses in the system.

Am I correct in assuming that air cannot be introduced into the system
unless there is serious corrosion or the like going on?

Only if you bleed it with the pump not running. If you try to bleed with
the CH pump running all bets are off. It can sometimes suck air in.

How much oxygen am I reintroducing repressurising the system?

Worst case not a great deal. And perhaps none at all if the repressuring
is done by a piston with the air in a bladder which is how the one I
have to sort out from time to time seems to be engineered.

It might be worth adding a corrosion inhibitor if it is a new
installation (elderly systems can react badly to any kind of change).

--
Regards,
Martin Brown

On Tue, 7 Nov 2017 10:41:09 +0000, Tim Watts
wrote:

On 07/11/17 10:29, AnthonyL wrote:

Am I correct in assuming that air cannot be introduced into the system
unless there is serious corrosion or the like going on?

Correct.


How much oxygen am I reintroducing repressurising the system?


It won't matter if you add inhibitor.

I think my problems started after adding inhibitor (following a PRV
replacement).

--
AnthonyL

On Tue, 7 Nov 2017 11:15:34 +0000, Tim Watts
wrote:

On 07/11/17 10:42, GB wrote:
On 07/11/2017 10:29, AnthonyL wrote:
I need to ensure I've got all the air out of my closed pressurised
system in order to resolve/eliminate another issue.Â* Pressure is
around 0.8bar when I start, down to about 0.5bar when I've finished
and I then repressurise.

The bleed screws are those little square ones at the back (not side)
of each radiator so when they squirt out they hit the wallpaper.

You don't own a towel?

Oh I forgot - small towell, rag, hanky, kitchen roll - all of these
should result in near zero spillage.

Yes I have a small plastic container sitting on a cloth on the floor
under the valve and a damp sponge trying to cover the squirt path of
the valve. SWIMBO demands zero spillage. The water, a bit like
peeing, seems to have its own ideas of which direction to go.

--
AnthonyL

On Tue, 7 Nov 2017 11:29:53 +0000, Martin Brown
wrote:

On 07/11/2017 10:29, AnthonyL wrote:


A couple sputter, water comes out but with a sputtering sound and/or a
whistling sound and this is where I'm confused. It seems no matter
how much I let out (I'm talking cup fulls not gallons) they still seem
to sputter. They sputtered yesterday, today and I expect they will
tomorrow.

Usually you find that any air in a system will mostly gravitate to one
or perhaps two radiators that are the highest in the system. The tops
will be noticeably cooler when the rest of it is hot if air is there.


I'm not sensing much difference. My old house had a top up tank, an
upper (bathroom) radiator often needed bleeding and it was obviously
cold on top and air (and just air) would come out until water came
out.

If there is a lot of air in a poorly designed system after refilling
then you will hear it bubbling up in any vertical pipe runs and a change
in pump noise when there is air going through it.

Is this air in the system or is it just the shape of the screw?

If it sputters it is probably from gasses in the system.

Am I correct in assuming that air cannot be introduced into the system
unless there is serious corrosion or the like going on?

Only if you bleed it with the pump not running. If you try to bleed with
the CH pump running all bets are off. It can sometimes suck air in.


I turn the whole boiler (CH and HW) to Off before starting.

How much oxygen am I reintroducing repressurising the system?

Worst case not a great deal. And perhaps none at all if the repressuring
is done by a piston with the air in a bladder which is how the one I
have to sort out from time to time seems to be engineered.

It might be worth adding a corrosion inhibitor if it is a new
installation (elderly systems can react badly to any kind of change).


It's an elderly system (like me). Never had any problems with my coal
fired back boiler CH system in 30yrs apart from the occasional bleed
of the bathrooom radiator mentioned and that was a two storey house
compared to this bungalow.

--
AnthonyL

On 07-Nov-17 10:29 AM, AnthonyL wrote:
I need to ensure I've got all the air out of my closed pressurised
system in order to resolve/eliminate another issue. Pressure is
around 0.8bar when I start, down to about 0.5bar when I've finished
and I then repressurise.

The bleed screws are those little square ones at the back (not side)
of each radiator so when they squirt out they hit the wallpaper.

The property is a bungalow so all radiators at ground level but the
pipes go up and over via the attic.

Anyhow most of the radiators instantly let out a silent stream of
water.

A couple sputter, water comes out but with a sputtering sound and/or a
whistling sound and this is where I'm confused. It seems no matter
how much I let out (I'm talking cup fulls not gallons) they still seem
to sputter. They sputtered yesterday, today and I expect they will
tomorrow.

Is this air in the system or is it just the shape of the screw?

Am I correct in assuming that air cannot be introduced into the system
unless there is serious corrosion or the like going on?

How much oxygen am I reintroducing repressurising the system?


Fit automatic bleed valves and stop worrying about it :-)


--
--

Colin Bignell

I'd have thought the up and down nature of the plumbing is an air trap
waiting to happen permanently myself.
Brian

--
----- -
This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please!
"AnthonyL" wrote in message
...
I need to ensure I've got all the air out of my closed pressurised
system in order to resolve/eliminate another issue. Pressure is
around 0.8bar when I start, down to about 0.5bar when I've finished
and I then repressurise.

The bleed screws are those little square ones at the back (not side)
of each radiator so when they squirt out they hit the wallpaper.

The property is a bungalow so all radiators at ground level but the
pipes go up and over via the attic.

Anyhow most of the radiators instantly let out a silent stream of
water.

A couple sputter, water comes out but with a sputtering sound and/or a
whistling sound and this is where I'm confused. It seems no matter
how much I let out (I'm talking cup fulls not gallons) they still seem
to sputter. They sputtered yesterday, today and I expect they will
tomorrow.

Is this air in the system or is it just the shape of the screw?

Am I correct in assuming that air cannot be introduced into the system
unless there is serious corrosion or the like going on?

How much oxygen am I reintroducing repressurising the system?

--
AnthonyL

On 07/11/2017 12:36, Nightjar wrote:
On 07-Nov-17 10:29 AM, AnthonyL wrote:
I need to ensure I've got all the air out of my closed pressurised
system in order to resolve/eliminate another issue.Â* Pressure is
around 0.8bar when I start, down to about 0.5bar when I've finished
and I then repressurise.

The bleed screws are those little square ones at the back (not side)
of each radiator so when they squirt out they hit the wallpaper.

The property is a bungalow so all radiators at ground level but the
pipes go up and over via the attic.

Anyhow most of the radiators instantly let out a silent stream of
water.

A couple sputter, water comes out but with a sputtering sound and/or a
whistling sound and this is where I'm confused.Â* It seems no matter
how much I let out (I'm talking cup fulls not gallons) they still seem
to sputter.Â* They sputtered yesterday, today and I expect they will
tomorrow.

Is this air in the system or is it just the shape of the screw?

Am I correct in assuming that air cannot be introduced into the system
unless there is serious corrosion or the like going on?

How much oxygen am I reintroducing repressurising the system?


Fit automatic bleed valves and stop worrying about it :-)


+1. Fitting one of these in the loft next to the water tank completely
eliminated any problems in my mother's bungalow.

AnthonyL wrote:
I need to ensure I've got all the air out of my closed pressurised
system in order to resolve/eliminate another issue. Pressure is
around 0.8bar when I start, down to about 0.5bar when I've finished
and I then repressurise.

SNIP

I think* the pressure should be 1.5 bar, mine is.
If the pressure drops to 0.8bar I'd say that you have a leak somewhere, we
did.

On 07/11/2017 10:29, AnthonyL wrote:
I need to ensure I've got all the air out of my closed pressurised
system in order to resolve/eliminate another issue. Pressure is
around 0.8bar when I start, down to about 0.5bar when I've finished
and I then repressurise.

The bleed screws are those little square ones at the back (not side)
of each radiator so when they squirt out they hit the wallpaper.

One of the bleed keys with attached receptacle might solve that:

http://amzn.eu/dGXFk4i

The property is a bungalow so all radiators at ground level but the
pipes go up and over via the attic.

Anyhow most of the radiators instantly let out a silent stream of
water.

A couple sputter, water comes out but with a sputtering sound and/or a
whistling sound and this is where I'm confused. It seems no matter
how much I let out (I'm talking cup fulls not gallons) they still seem
to sputter. They sputtered yesterday, today and I expect they will
tomorrow.

Some have the outlet positioned such that you can't actually bleed all
the air out - there will be a little pocket of air at the top.

Is this air in the system or is it just the shape of the screw?

Am I correct in assuming that air cannot be introduced into the system
unless there is serious corrosion or the like going on?

No... some will come with the fresh water - so each time you add more a
little air will also be added.

You can also get air drawn in if you have a very slow leak somewhere.

How much oxygen am I reintroducing repressurising the system?

A little but not much. That is one of the things the corrosion inhibitor
is for - to mop up any excess O2.


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On Tue, 7 Nov 2017 14:47:00 +0000, newshound
wrote:

On 07/11/2017 12:36, Nightjar wrote:
On 07-Nov-17 10:29 AM, AnthonyL wrote:
I need to ensure I've got all the air out of my closed pressurised
system in order to resolve/eliminate another issue.Â* Pressure is
around 0.8bar when I start, down to about 0.5bar when I've finished
and I then repressurise.

The bleed screws are those little square ones at the back (not side)
of each radiator so when they squirt out they hit the wallpaper.

The property is a bungalow so all radiators at ground level but the
pipes go up and over via the attic.

Anyhow most of the radiators instantly let out a silent stream of
water.

A couple sputter, water comes out but with a sputtering sound and/or a
whistling sound and this is where I'm confused.Â* It seems no matter
how much I let out (I'm talking cup fulls not gallons) they still seem
to sputter.Â* They sputtered yesterday, today and I expect they will
tomorrow.

Is this air in the system or is it just the shape of the screw?

Am I correct in assuming that air cannot be introduced into the system
unless there is serious corrosion or the like going on?

How much oxygen am I reintroducing repressurising the system?


Fit automatic bleed valves and stop worrying about it :-)


+1. Fitting one of these in the loft next to the water tank completely
eliminated any problems in my mother's bungalow.

I'll enquire about them - do they work on a closed pressured system?

And how come everything has been fine for 2 years before I had some
boiler work?

--
AnthonyL

On Tue, 7 Nov 2017 17:56:01 -0000, "Mr Pounder Esquire"
wrote:

AnthonyL wrote:
I need to ensure I've got all the air out of my closed pressurised
system in order to resolve/eliminate another issue. Pressure is
around 0.8bar when I start, down to about 0.5bar when I've finished
and I then repressurise.

SNIP

I think* the pressure should be 1.5 bar, mine is.
If the pressure drops to 0.8bar I'd say that you have a leak somewhere, we
did.



I've dropped the pressure to that level. AIUI it is within spec. I
can increase it if it has any bearing on my problem, it isn't leaking
(since the PRV was replaced).
--
AnthonyL

On Tue, 7 Nov 2017 18:12:08 +0000, John Rumm
wrote:

On 07/11/2017 10:29, AnthonyL wrote:
I need to ensure I've got all the air out of my closed pressurised
system in order to resolve/eliminate another issue. Pressure is
around 0.8bar when I start, down to about 0.5bar when I've finished
and I then repressurise.

The bleed screws are those little square ones at the back (not side)
of each radiator so when they squirt out they hit the wallpaper.

One of the bleed keys with attached receptacle might solve that:

http://amzn.eu/dGXFk4i


Doesn't work on little square bleed valves that are on the back of the
panel

https://www.diynot.com/diy/media/untitled.85254/full



--
AnthonyL