Gas meter test point

[David Hearn]

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

[Andy Hall]

That's the test point.

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 c*ck 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.

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

.andy

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[John Armstrong]

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

1 inch of water = 2.49 mbar

[Set Square]

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

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"]

[baz]

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

[Peter Taylor]

baz wrote

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

[Ed Sirett]

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

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.

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

[Ed Sirett]

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

[tarquinlinbin]

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