Can Smart Meters cause reduction in Gas pressure?

Zandoni

The meter will not cause a pressure drop, especially as the test point for the meter is on the outlet.

alanwsg

Several people have said that the smart meter fitter wouldn't have touched the regulator.
I think that's wrong - when my smart meter was fitted, he replaced the regulator with a new one.

I asked about this as the regulator in place was only a year or so old (It had to be replaced when I had a combi boiler fitted - the boiler man called the gas company and they came out in less than an hour).
He said they always replace the regulator with the smart meter.

fcjf

Zandoni said:

The meter will not cause a pressure drop, especially as the test point for the meter is on the outlet.

So when the Baxi report states pressure at the meter is 19mb, this is at the point that the gas enters my domestic pipework?

doodling

Hi,

fcjf said:

Zandoni said:

The meter will not cause a pressure drop, especially as the test point for the meter is on the outlet.

So when the Baxi report states pressure at the meter is 19mb, this is at the point that the gas enters my domestic pipework?

Yes.

As stated previously, that is greater than 18.5mBar so it is fine.

Zandoni

fcjf said:

Zandoni said:

The meter will not cause a pressure drop, especially as the test point for the meter is on the outlet.

So when the Baxi report states pressure at the meter is 19mb, this is at the point that the gas enters my domestic pipework?

Yes, you can see the test point on the outlet of the meter.

fcjf

I checked the commissioning report from when the boiler was installed in 2011 and it records a reading of 20mb at the boiler gas inlet. I guess that this means that the pipework was capable of delivering 20mb from what would be a max pressure at the meter of between 20 - 22mb. If good practice was a max 1mb drop between meter and appliance then I assume that there was a max of 21mb at the meter, or at most 22mb.

I take from this that if nothing has changed to the pipework then with a meter pressure of 19mb I should be getting 18mb at the appliance or at the very worst 17mb.

The only change to any part of the installation is the smart meter so I cannot get away from feeling the installation of the smart meter has affected the pressure. I appreciate that this is a layman's view but I don't know how a blockage could have occurred otherwise. I'm still unsure what I do from here, get an independent engineer out to take readings and price up new pipework or ask E-ON to remove the Smart Meter or something else, any advice?

jefaz07

The pressure drop is AFTER your meter. Regardless of incoming pressure the working pressure between outlet and appliance is >1mb. 

You can get pressure loss across a meter called meter absorption which can be up to 4mb, but this isn’t the issue in your case.
As a side, I have found lots of new regulators to be set very low from factory and had to adjust them, normally to 21mb. Even If you got a pressure increase there you’d still have >1mb from meter outlet to appliance but maybe above 17mb. Gas safe and networks don’t like adjusting the reg to offset bad installation paperwork. 

doodling

Hi,

fcjf said:

I checked the commissioning report from when the boiler was installed in 2011 and it records a reading of 20mb at the boiler gas inlet. I guess that this means that the pipework was capable of delivering 20mb from what would be a max pressure at the meter of between 20 - 22mb. If good practice was a max 1mb drop between meter and appliance then I assume that there was a max of 21mb at the meter, or at most 22mb.

You can't draw any conclusions without knowing the circumstances of that 2011 pressure measurement at the boiler.  Was the pressure measured with the boiler running at full power (in which case that pressure will be whatever the pressure at the meter was minus the pressure drop in your pipework), or was it with the boiler off (in which case the pressure will be the same as the pressure at the meter), or was it with the boiler modulated down to a lower power (so the pressure will be somewhere in between the two) - it should have been the first one of those but sometimes people make mistakes (or don't do a proper job)?

I take from this that if nothing has changed to the pipework then with a meter pressure of 19mb I should be getting 18mb at the appliance or at the very worst 17mb.

If your assumptions about the measurements are correct, yes.  What evidence do you have that your assumptions are correct?

The only change to any part of the installation is the smart meter so I cannot get away from feeling the installation of the smart meter has affected the pressure. I appreciate that this is a layman's view but I don't know how a blockage could have occurred otherwise. I'm still unsure what I do from here, get an independent engineer out to take readings and price up new pipework or ask E-ON to remove the Smart Meter or something else, any advice?

Your supplier doesn't care whether the installation of the smart meter has affected the pressure, they only care if the pressure at the meter is no longer within the permitted limits.  You have previously told us that the pressure at the meter is 19mBar, that is within permitted limits so your supplier is not at fault (providing that more than 18.5mBar is maintained even with the boiler running at maximum power - I assume that the 19mBar at the meter was measured with the boiler at maximum power?).

If you know the details of the pipework (length, number of bends, etc.), you can calculate the expected pressure drop for a given gas flow (which will be specified in your boiler manual) so you can work out for yourself whether the pressure drop you are seeing is consistent with the pipework or whether there may be an obstruction (or the pressures incorrectly measured).  This should really be the first thing you do as it very quickly determines where the problem is likely to be and is something you can do yourself.

If you don't believe the fitter who has just checked the pressures then get another fitter in to do the same.  If they come up with the same figures then the answer is to reduce the pressure drop in your pipework.  If they come up with different figures then the answer might be to do nothing (if the pressure at the boiler is acceptable) or to complain to your supplier (if the pressure at the meter is below 18.5mBar).

If you find an obstruction in your pipework that was caused by the meter installer then I expect you could claim the costs of fixing it from your supplier.  Your supplier's stance will almost certainly be that until you have found a mistake in what they have done then the issue is nothing to do with them.

The only other point is whether there are any other gas appliances connected to your supply.  These also need to be taken into account and the pipework sized accordingly - the pressure at the boiler should be maintained even if other appliances (e.g. a gas hob) are fully turned on.

FreeBear

doodling said: If you know the details of the pipework (length, number of bends, etc.), you can calculate the expected pressure drop for a given gas flow (which will be specified in your boiler manual) so you can work out for yourself whether the pressure drop you are seeing is consistent with the pipework or whether there may be an obstruction (or the pressures incorrectly measured).  This should really be the first thing you do as it very quickly determines where the problem is likely to be and is something you can do yourself.

Follow the link in this post for details on how to calculate the expected pressure drop in the pipe between meter & boiler - https://forums.moneysavingexpert.com/discussion/comment/80549086/#Comment_80549086

If you don't know the difference between a bend and an elbow, go for the numbers in the elbow column.

fcjf

I have measured the pipework and bends and calculated the expected pressure drop as 1.54mb. This is in excess of the allowable 1mb drop between meter and appliance but also 1.5mb less than I am achieving at the boiler. Does this indicate a blockage in the pipework?

Note. the gas pipework is the original from when the house was built in 1987, I guess the regs on allowable pressure drop may not have been in place then but when the current boiler was installed in 2011 the calculation should have been carried out and the pipework size increased accordingly?