Open vent heating pumping over

[Tom Pickles]

My heating's been pumping over for a while now, spilling over the overflow from my header tank. I can't seem to get to the bottom of the problem.

I've extended the height of the open vent which is now two feed above the top of the header tank. I have also bent the arm of the float valve so that the water level in the header tank is about five inches high, but it still pumps over and out of the overflow.

I recently put fernox F3 through the system, flushed it all out and re-treated. I also descaled the boiler using fernox DS40 as part of the same job.

I have read that the aerjec air separator things can get blocked and cause pumping over, but I'm not sure how I would re-pipe it if I removed it, or perhaps it isn't a problem?!

Here's a photo I took of my pipe setup in the airing cupboard (ignore the leaky hot tank, that was quickly replaced):

http://i.imgur.com/iF75oHt.jpg

The pump flows from top to bottom.

Any ideas guys?

Thanks,

Tom

[Piers]

I am told by a plumper aquaintance that you shouldn't get pumping over
if you have an aerjec. In fact I recently fitted an aerjec after a long
period of pumping over and it cured it. When I cut out the existing
pipework to fit the aerjec I found the flow mostly blocked with a
crystalline structure immediately after the old feed. It was rock solid
- can't imagine F3 or anything shifting it (and I did put some cleaner
in at one point). (Of course, the aerjec might have had nothing to do
with curing my problems - replacing the partially blocked pipe might
have done. Unsure as to cause and effect here.)

Note that the aerjec instructions state that the vent must be vertically
upwards. Pretty sure yours is horizontal. See
http://www.docstoc.com/docs/48138840/Circulating-Pumps-Aerjec-scalding
(crappy site, sorry).

[John Rumm]

On 26/01/2014 17:41, Tom Pickles wrote:

> Here's a photo I took of my pipe setup in the airing cupboard (ignore
> the leaky hot tank, that was quickly replaced):
>
> http://i.imgur.com/iF75oHt.jpg
>
> The pump flows from top to bottom.
>
> Any ideas guys?

It looks like the vent is on the suction side pump... is that right?
(make pumpover unlikely - although can suck air into the system)

Sometimes making a combined vent and F+E connection on the suction side
solves the problem. So you take the F&E pipe and tee it into the vent a
foot or so above the CH vent connection.

--
Cheers,

John.

/=================================================================\
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\=================================================================/

[Tom Pickles]

On Sunday, January 26, 2014 6:21:30 PM UTC, John Rumm wrote:
> On 26/01/2014 17:41, Tom Pickles wrote:
>
>
>
> > Here's a photo I took of my pipe setup in the airing cupboard (ignore
>
> > the leaky hot tank, that was quickly replaced):
>
> >
>
> > http://i.imgur.com/iF75oHt.jpg
>
> >
>
> > The pump flows from top to bottom.
>
> >
>
> > Any ideas guys?
>
>
>
> It looks like the vent is on the suction side pump... is that right?
>
> (make pumpover unlikely - although can suck air into the system)

Yes I think you're correct. As Piers has indicated, the installation of the Aerjec is likely incorrectly oriented, rendering it useless.

> Sometimes making a combined vent and F+E connection on the suction side
>
> solves the problem. So you take the F&E pipe and tee it into the vent a
>
> foot or so above the CH vent connection.

Make a "H" type of piping setup linking the F&E to the vent? What would you reccommend doing with the Aerjec? (bearing in mind I'm reasonably sure it's blocked).

Thanks for your response.

[Roger Mills]

On 26/01/2014 17:41, Tom Pickles wrote:

Have you actually watched water discharging from the vent pipe into the
F&E tank - or are you surmising that it does because it's going out of
the overflow?

What is the difference in level between the level controlled by the ball
valve and the level needed to overflow? If this difference is large (say
> 6") the static level is unlikely to increase by this amount just due
to expansion. Even if pumping over *is* occurring, that in itself won't
raise the level in the F&E tank - so if its rising above the overflow,
something else must be happening.

Is there a large cold tank in the attic, as the header for the DHW
system? If so, how does the water level in that compare with the level
in the F&E tank. If it's higher, have you considered the possibility
that the coil in your hot cylinder may be shot - resulting in water from
the DHW system leaking into to primary circuit?
--
Cheers,
Roger
____________
Please reply to Newsgroup. Whilst email address is valid, it is seldom
checked.

[John Rumm]

On 26/01/2014 19:20, Tom Pickles wrote:

>> It looks like the vent is on the suction side pump... is that
>> right?
>>
>> (make pumpover unlikely - although can suck air into the system)
>
> Yes I think you're correct. As Piers has indicated, the installation
> of the Aerjec is likely incorrectly oriented, rendering it useless.
>
>> Sometimes making a combined vent and F+E connection on the suction
>> side
>> solves the problem. So you take the F&E pipe and tee it into the
>> vent a
>> foot or so above the CH vent connection.
>
> Make a "H" type of piping setup linking the F&E to the vent?

Kind of...

Vent F&E
# #
# #
# #
# #
# #
##########
#
#
######### Pump ->

The suction side ought not pump over, and the F&E teed into it means it
ought not suck in air either.

However a blockage could mess things up in any system, so it seems
prudent to eliminate that first. A blockage between vent and pump might
do it.

> What
> would you reccommend doing with the Aerjec? (bearing in mind I'm
> reasonably sure it's blocked).

If its blocked you may as well dispense with it.

[Tom Pickles]

Thanks for the clarification John. I'll amend the pipework as you suggest and remove the air separator.

[Dave Liquorice]

On Mon, 27 Jan 2014 00:28:42 -0800 (PST), Tom Pickles wrote:

>> Vent F&E
>> # #
>> # #
>> # #
>> # #
>> # #
>> ##########
>> #
>> #
>> ######### Pump ->
>>
>> The suction side ought not pump over, and the F&E teed into it
means it
>> ought not suck in air either.
>>
>> However a blockage could mess things up in any system, so it seems

>> prudent to eliminate that first.

> Thanks for the clarification John. I'll amend the pipework as you
> suggest and remove the air separator.

I'm not sure the arrangement show is a good idea. A favorite place
for lime scale to form is where the feed joins the main loop, some
one in here has already mentioned that from their direct experience.
In the above layout if that stub between the main loop and vent/F&E
gets blocked things could get "interesting" as it would also block
the vent...

This is a more common arrangement, the space between the vent and F&E
should be < 100 mm:

Vent F&E
# #
# #
# #
# #
# #

################## Pump ->

--
Cheers
Dave.

[Tom Pickles]

Hi Dave,

As you can see from the photo of my airing cupboard, there isn't a whole lot of room to play with in terms of current pipe layout. The hot feed from the boiler comes up from the floor in parallel with and within an inch or so of the pump itself. I'd have to tee in either the vent or the feed from the F&E tank in there to go with the layout you suggest.

Would you recommend I tee in the vent at the top, where the Aerjec is now, and the cold feed below it, tee'd into the rising hot feed?

Thanks for responding.

[Onetap]

On Sunday, January 26, 2014 5:41:08 PM UTC, Tom Pickles wrote:

> Any ideas guys?

First off, get yourself a magnet and check all the pipes around the cold feed.

If there has been a longstanding leak, the limescale will precipitate at the point where the cold water enters the heating system, forming a solid blockage with magnetite sludge.

The standard remedy is to cut out the Tee and replace it.

You might be able to descale the Aerejec thing, but I'm told descaler is ineffective on the magnetite/scale deposits and I've never tried it.

[Onetap]

On Monday, January 27, 2014 4:23:00 PM UTC, Onetap wrote:
> On Sunday, January 26, 2014 5:41:08 PM UTC, Tom Pickles wrote:
>
>
>
> > Any ideas guys?
>
>
>

> First off, get yourself a magnet...

...assuming your water is hard.

[Tom Pickles]

On Monday, January 27, 2014 4:23:00 PM UTC, Onetap wrote:

There isn't a problem with the hot water tank. The height of the water in the header tank drops to a normal level when the system is cold. I've checked with a magnet and it's all ok. I also fitted one of these a while back: http://www.spirotrapmb3.co.uk/

I could replace the Aerjec for £12 but most things I've read suggests they are better off removed. Plus, it looks like mine's been fitted incorrectly by the plumber when the house was built, and the plumbing doesn't lend itself to being majorly re-configured.

[Brian]

replying to Tom Pickles, Brian wrote:
Hi tom i have taken a look at your aerject layout in the picture posted and
straight away i can see where your problem lies , if you look at the pump you
will see that the grundfos logo printed on the front of the pump face is
upside down and the speed rotation arrow printed near the bleed screw in the
middle of the pump is showing the pump turning anticlockwise , therefore this
pump is actually fitted upside down meaning the positive pressure of the pump
is forcing water from the return side of the boiler into the aerject causing
the water in the vent pipe off the aerject to rise above the expansion tank
level and over into the tank as steam/water when the boiler is working at
maximum temperature.The purpose of the aerject is to reduce excess negative
and positive pressures being created by the pump by virtue that the open vent
pipe is taken close to the neutral point of the system which is always where
the cold feed from the expansion tank connects into the system , in addition
to this the aerject has a 22mm port ontop to remove air bubbles as the pump
sucks water through the device and this is achieved by slowing the water flow
down as it enters a larger void spave within the aerject reducing the velocity
pressure and giving time for the air bubble to rise out of the aerject void
space and out up the vent pipe and into the atmosphere above the expansion
tank. So my suggestion would be to turn the pump the right way up and if
problems still persist to re pipe the aeject making sure the vent port is
facing upwards and your flow from the boiler goes into the top side
connnection the flow to the heating system goes directly below it on the same
side and finally your cold feed pipe goes to the connection opposite the flow
connections to finally resolve your problems, dont forget to desludge your
aerject completely before refitting , hhope this was useful to you and your
fellow engineers,regards Brian (Domestic boiler technician)

--
posted from
http://www.homeownershub.com/uk-diy/open-vent-heating-pumping-over-952282-.htm

[Andy Burns]

Brian wrote:

> Hi tom i have taken a look at your aerject layout in the picture posted and
> straight away i can see where your problem lies

Clearly you've given a detailed and well-meaning response to Tom's
problem, unfortunately it's over two years too late ...

HomeOwnersHub (HOH) is one of a number of web sites that provide a
gateway to one or more USENET newsgroups. In this particular case it
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For some background and links about usenet groups and how they are
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Like good comedy, Timing is everything
=======================================

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So when replying to a post, please take careful note of the date on
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post concerning a problem with someone's central heating, if the problem
occurred in 2006 - One, they have probably fixed it by now, and two,
most readers of your message won't be able to see what you are replying
to - so it will make little sense!

(Although many news servers won't retain posts to a group for an
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Quoting
=======

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irritate others!)

[Dave Plowman (News)]

In article <dop68k...@mid.individual.net>,

Andy Burns <feb2017...@adslpipe.co.uk> wrote:
> > Hi tom i have taken a look at your aerject layout in the picture
> > posted and straight away i can see where your problem lies

> Clearly you've given a detailed and well-meaning response to Tom's
> problem, unfortunately it's over two years too late ...

Probably converted to a sealed system by now. ;-)

--
*Reality? Is that where the pizza delivery guy comes from?

Dave Plowman da...@davenoise.co.uk London SW
To e-mail, change noise into sound.

[Kevin. Professional domestic gas tech and heating consultant.]

replying to Onetap, Kevin. Professional domestic gas tech and heating
consultant. wrote:
Hi guys, I would like to add: if the water colour in your system is black,
that’s hydrogen deposited as sludge in your system once the water has become
over saturated and released as much as it can as hydrogen gas. You may have
bled the radiators thinking it was air. A good de-sludging non de scaling
agent, X100 or furnox will do. If the water colour is orange or red, that’s
due to air entering the system via the header tank for the heating system. The
desludging agents mentioned will have little affect on this. You need to have
the system power flushed and this can take up to a day or so. The “pumping
over” is mainly due to a low pitched roof which prevents the header tank to
be installed at the correct heigh. The Fill and Vent should not be installed
by the use of tee fittings. A Myson airseperator or a Tower Air separator
should be installed correctly and the distance between the exit of this peice
of equipment and the first pump valve is crucial. If the “pumping over is
the main problem, before you spend money, check for a blocked cold feed from
the tank to where it enters your system. It really is a professional job yet
be ware of rip off merchants. Also when this work is done take care of your
system and do not trust the nationals out there who are only out for your
money. Kindest regards.

--
for full context, visit https://www.homeownershub.com/uk-diy/open-vent-heating-pumping-over-952282-.htm

[John Rumm]

On 04/04/2018 21:44, Kevin. Professional domestic gas tech and heating

consultant. wrote:

> Hi guys, I would like to add: if the water colour in your system is black,
> that’s hydrogen deposited as sludge in your system once the water has
> become

[snip]

Yup might have been a handy response if were not for the fact you are
FOUR YEARS too late... Do you suppose looking at the date of the
original query would not be a good idea?

(especially as most people reading this won't even know what you are
replying to!)

[Johnny B Good]

On Wed, 04 Apr 2018 22:09:51 +0100, John Rumm wrote:

> On 04/04/2018 21:44, Kevin. Professional domestic gas tech and heating
> consultant. wrote:
>
>> Hi guys, I would like to add: if the water colour in your system is
>> black,
>> that’s hydrogen deposited as sludge in your system once the water has
>> become
>
> [snip]
>
> Yup might have been a handy response if were not for the fact you are
> FOUR YEARS too late... Do you suppose looking at the date of the
> original query would not be a good idea?
>
> (especially as most people reading this won't even know what you are
> replying to!)

One *single* entry in my killfile blocks every single HOH posting. The
only evidence of HOH postings I ever see are in quotage in follow ups
like this one. Since there's virtually zero benefit in replying to
*anyone* posting via the HOH portal, killfiling HOH postings seems the
kindest thing to do for all concerned. Just a suggestion. :-)

--
Johnny B Good

[John Rumm]

To be fair there have been one or two genuine original posts... but they
are few and far between!

[tabb...@gmail.com]

On Thursday, 5 April 2018 11:51:09 UTC+1, John Rumm wrote:
> On 04/04/2018 23:04, Johnny B Good wrote:
> > On Wed, 04 Apr 2018 22:09:51 +0100, John Rumm wrote:
> >
> >> On 04/04/2018 21:44, Kevin. Professional domestic gas tech and heating
> >> consultant. wrote:
> >>
> >>> Hi guys, I would like to add: if the water colour in your system is
> >>> black,
> >>> that’s hydrogen deposited as sludge in your system once the water has
> >>> become
> >>
> >> [snip]
> >>
> >> Yup might have been a handy response if were not for the fact you are
> >> FOUR YEARS too late... Do you suppose looking at the date of the
> >> original query would not be a good idea?
> >>
> >> (especially as most people reading this won't even know what you are
> >> replying to!)
> >
> > One *single* entry in my killfile blocks every single HOH posting. The
> > only evidence of HOH postings I ever see are in quotage in follow ups
> > like this one. Since there's virtually zero benefit in replying to
> > *anyone* posting via the HOH portal, killfiling HOH postings seems the
> > kindest thing to do for all concerned. Just a suggestion. :-)
>
> To be fair there have been one or two genuine original posts... but they
> are few and far between!

Why do hoh only get idiots posting? Could it be the sensible ones see the date & walk away?

[John Rumm]

Dunno... If you want a web portal to usenet, then as they go its not too
bad. It even allows proper quoting if you know how to drive it. Perhaps
its all too difficult for the facebook generation!

[Vir Campestris]

On 04/04/2018 22:09, John Rumm wrote:
> On 04/04/2018 21:44, Kevin. Professional domestic gas tech and heating
> consultant. wrote:
>
>> Hi guys, I would like to add: if the water colour in your system is
>> black,
>> that’s hydrogen deposited as sludge in your system once the water has
>> become
>
> [snip]
>
> Yup might have been a handy response if were not for the fact you are
> FOUR YEARS too late... Do you suppose looking at the date of the
> original query would not be a good idea?
>
> (especially as most people reading this won't even know what you are
> replying to!)
>

I'm not an anything to do with heating. But I am a bit surprised that
you agree with him that the black stuff is hydrogen deposited as sludge.
I thought it was iron (II) oxide...

Andy

[John Rumm]

Sorry, was intending to imply agreement with what he said...

> I thought it was iron (II) oxide...

Indeed it is.

[Roger Hayter]

John Rumm <see.my.s...@nowhere.null> wrote:

> On 06/04/2018 21:12, Vir Campestris wrote:
> > On 04/04/2018 22:09, John Rumm wrote:
> >> On 04/04/2018 21:44, Kevin. Professional domestic gas tech and heating
> >> consultant. wrote:
> >>
> >>> Hi guys, I would like to add: if the water colour in your system is
> >>> black,
> >>> that's hydrogen deposited as sludge in your system once the water has
> >>> become
> >>
> >> [snip]
> >>
> >> Yup might have been a handy response if were not for the fact you are
> >> FOUR YEARS too late... Do you suppose looking at the date of the
> >> original query would not be a good idea?
> >>
> >> (especially as most people reading this won't even know what you are
> >> replying to!)
> >>
> > I'm not an anything to do with heating. But I am a bit surprised that
> > you agree with him that the black stuff is hydrogen deposited as sludge.
>
> Sorry, was intending to imply agreement with what he said...
>
> > I thought it was iron (II) oxide...
>
> Indeed it is.

Apparently, meaning I just looked it up, magnetite, which contains
Fe(II) and Fe(III) is more stable than Fe(II)0 (which exists as Fe(OH)2
in water) in reducing conditions.

Just as a matter of interest!


--

Roger Hayter

[Fredxx]

On 04/04/2018 23:04, Johnny B Good wrote:

The kindest thing would be to add a criteria of "Re:" in the title.

Thankfully HOH replies are few and far between, perhaps an indication of
the traffic they get!