I'm trying to work out the current gas pressures in our house prior to
getting a new boiler (to make sure the current pipework is suitable).

Looking at Ed's FAQ, I should be able to put a manometer onto the meter and
find out the pressure there - however I can't see any such test points.
I've got an old governor on the input side of the meter and can't see any
test points on there. The meter is a reasonably new BTR Eurometers Ltd made
digital one. The output from the meter has a screw thing (about 5mm
diameter) on the output collar - though I don't want to unscrew that unless
I'm sure I know what it is.

As I understand it, the pressure from the govenor should be 20mbar +/-
1mbar - however the Ideal Classic SE boiler claims "a *minimum* gas pressure
of 20 mbar MUST be available at the boiler inlet, with the boiler operating.
So before any pipework runs are taken into account, my pressure may be to
low anyway.

I'll check the pressures at the current boiler and see what's there. I
really don't want to be doing any new pipework as the pipes run under the
kitchen floor and behind the kitchen cupboards....

Incidentally, where's the best place to buy a manometer from? I've seen one
online for about £15 + VAT (glass) and cheaper for plastic. Any preference
as to which to get assuming I'll probably neverUID it again - or at least,
not for a while.

Thanks

David

On Mon, 26 Jan 2004 16:36:23 -0000, "David Hearn"
wrote:

I'm trying to work out the current gas pressures in our house prior to
getting a new boiler (to make sure the current pipework is suitable).

Looking at Ed's FAQ, I should be able to put a manometer onto the meter and
find out the pressure there - however I can't see any such test points.
I've got an old governor on the input side of the meter and can't see any
test points on there. The meter is a reasonably new BTR Eurometers Ltd made
digital one. The output from the meter has a screw thing (about 5mm
diameter) on the output collar - though I don't want to unscrew that unless
I'm sure I know what it is.

That's the test point.


As I understand it, the pressure from the govenor should be 20mbar +/-
1mbar - however the Ideal Classic SE boiler claims "a *minimum* gas pressure
of 20 mbar MUST be available at the boiler inlet, with the boiler operating.
So before any pipework runs are taken into account, my pressure may be to
low anyway.

I'll check the pressures at the current boiler and see what's there. I
really don't want to be doing any new pipework as the pipes run under the
kitchen floor and behind the kitchen cupboards....

Make sure that you connect to the correct test point if there is more
than one. My old boiler had a burner test point for setting up.
That's interesting, but useless for testing pressure drop on the
pipework since it is after the regulator in the gas valve. There
should be one on the input side as well, if need be in the isolating
cock to the boiler. My old boiler didn't have one but the new one
does. It is that which is the one to use.

It would be worth timing the meter as well (no other gas appliances in
use) to see what the gas rate is.


Incidentally, where's the best place to buy a manometer from? I've seen one
online for about £15 + VAT (glass) and cheaper for plastic. Any preference
as to which to get assuming I'll probably neverUID it again - or at least,
not for a while.

B&Q have them as well for about this price.



Thanks

David


..andy

To email, substitute .nospam with .gl

On Mon, 26 Jan 2004 16:36:23 -0000, David Hearn wrote:

Incidentally, where's the best place to buy a manometer from? I've seen one
online for about £15 + VAT (glass) and cheaper for plastic. Any preference
as to which to get assuming I'll probably neverUID it again - or at least,
not for a while.


You could make your own if it only a one off use, might even be free if you
have some suitable tube. Several sites describing the construction,
although tend to be american and using inches of water as the units of
pressure, eg http://www.rverscorner.com/articles/manometer.html
1 inch of water = 2.49 mbar

In an earlier contribution to this discussion,
David Hearn wrote:

I'm trying to work out the current gas pressures in our house prior to
getting a new boiler (to make sure the current pipework is suitable).

Looking at Ed's FAQ, I should be able to put a manometer onto the
meter and find out the pressure there - however I can't see any such
test points. I've got an old governor on the input side of the meter
and can't see any test points on there. The meter is a reasonably
new BTR Eurometers Ltd made digital one. The output from the meter
has a screw thing (about 5mm diameter) on the output collar - though
I don't want to unscrew that unless I'm sure I know what it is.

The test point on my meter is on the output collar. There is a a little ipe
coming out horizontally, with a slightly flared end. There is screw screwed
into the end, which must be removed in order to fit a manometer


Incidentally, where's the best place to buy a manometer from? I've
seen one online for about £15 + VAT (glass) and cheaper for plastic.
Any preference as to which to get assuming I'll probably neverUID it
again - or at least, not for a while.


This is *uk.d-i-y* - Make your own! I made one from a piece of floorboard, a
length of clear plastic tubing attached to it in a U shape (with a long
piece one side to connect to the test-point) and a sheet of graph paper
behind the tube. It needs to be half filled with water - then you can read
the pressure in inches (or cms depending on the graph paper) of water, and
then convert to millibars. [From a rough calc, 1" water = approx 2.75 mB
(but you'll need to find the exact figure) - so your manometer needs to
cater for height differences of around 8"]

--
Cheers,
Set Square
______
Please reply to newsgroup. Reply address is Black Hole!

"David Hearn" wrote in message
...
I'm trying to work out the current gas pressures in our house prior to
getting a new boiler (to make sure the current pipework is suitable).

snip
Incidentally, where's the best place to buy a manometer from? I've seen
one
online for about £15 + VAT (glass) and cheaper for plastic. Any
preference
as to which to get assuming I'll probably neverUID it again - or at
least,
not for a while.

Thanks

David

David.
You could make your own Manometer.
All you need is some clear plastic tube.
Attach it to a board in the shape of a long "U".
Half fill it with water, add some food colouring if you want, to enable you
to see it better.
1 millibar = 10.2 mm of water.
But as you have a "U" you need to add the bit going down to the bit going
up.
So if you are looking for 20 millibar, the water should rise 51mm on one
side and drop 51mm on the other.
You should have a test point on your gas valve in your boiler.
Use a piece of rubber tube to connect this to one side of your Manometer.
Baz

baz wrote
You should have a test point on your gas valve in your boiler.

Out of interest, when you perform a gas pressure test on the whole installation
which valves should be open or closed? Specifically, after charging up the
pipework are you supposed to close the main valve or leave it open? And what is
the criteria for pass or fail please?

I found slight pressure deviations when the main supply valve was open, which
disappeared when I closed it. Then I thought I'd discovered a major leak until
I remembered it was the permanent pilots on our old cooker. As you can tell,
I'm not much of a "competent person" when it comes to gas fitting 8-{/

Peter

On Mon, 26 Jan 2004 16:36:23 +0000, David Hearn wrote:

I'm trying to work out the current gas pressures in our house prior to
getting a new boiler (to make sure the current pipework is suitable).

Looking at Ed's FAQ, I should be able to put a manometer onto the meter and
find out the pressure there - however I can't see any such test points.
I've got an old governor on the input side of the meter and can't see any
test points on there. The meter is a reasonably new BTR Eurometers Ltd made
digital one. The output from the meter has a screw thing (about 5mm
diameter) on the output collar - though I don't want to unscrew that unless
I'm sure I know what it is.

That's it. The plug in the fitting has a suicidal wish to become lost -
you have been warned.


As I understand it, the pressure from the govenor should be 20mbar +/-
1mbar - however the Ideal Classic SE boiler claims "a *minimum* gas pressure
of 20 mbar MUST be available at the boiler inlet, with the boiler operating.
So before any pipework runs are taken into account, my pressure may be to
low anyway.

I'm sure the FAQ say the outlet of the meter should be 21mbar +/- 1.
The Ideal Classic SE seems rather demanding in this matter.
In the absense of manufactures data you would assume that a _minimum_ of 19
(the lower bound of 20 +/- 1) would be required.
Most boilers I've fitted have said they are happy with a minimum of
18mbar.


I'll check the pressures at the current boiler and see what's there. I
really don't want to be doing any new pipework as the pipes run under the
kitchen floor and behind the kitchen cupboards....

Incidentally, where's the best place to buy a manometer from? I've seen one
online for about £15 + VAT (glass) and cheaper for plastic. Any preference
as to which to get assuming I'll probably neverUID it again - or at least,
not for a while.

For a one time use it is probably better to make your own. 98mm of height
difference is 10 mBar

--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html

On Mon, 26 Jan 2004 21:34:32 +0000, Ed Sirett wrote:


For a one time use it is probably better to make your own. 98mm of height
difference is 10 mBar



Oops sorry I meant 10mBar is 102mm of height difference.

--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html

On Mon, 26 Jan 2004 21:34:39 +0000, "Ed Sirett"
wrote:

On Mon, 26 Jan 2004 16:36:23 +0000, David Hearn wrote:

I'm trying to work out the current gas pressures in our house prior to
getting a new boiler (to make sure the current pipework is suitable).

Looking at Ed's FAQ, I should be able to put a manometer onto the meter and
find out the pressure there - however I can't see any such test points.
I've got an old governor on the input side of the meter and can't see any
test points on there. The meter is a reasonably new BTR Eurometers Ltd made
digital one. The output from the meter has a screw thing (about 5mm
diameter) on the output collar - though I don't want to unscrew that unless
I'm sure I know what it is.

That's it. The plug in the fitting has a suicidal wish to become lost -
you have been warned.

As Ed says,thats it!!,unscrew and refit it with a small
screwdriver,dont overtighten it or it may snap and/or leak and you may
be charged for a new meter if you damage it!!

joe