Gas Fire Working Pressure

[dazpoynter]

Hi

Just had a new gas fire fitted and the working pressure was recorded at 20mbar at the fire with it running on full which is what the manufacture requires but this was with all the other appliances off e.g boiler and cooker.

When the boiler was turned on it dropped to just under 19mbar which is below what the manufacture requires.

Is this ok and should it have been tested with the other appliances off?

Thanks

 

[BingoBongo]

did the fitter check the pressure at the meter? Most likely cause is undersized pipework and the fitter should have taken this into account and given a cost to fix it

 

[45yearsagasman]

19/20 mbar will not make the slightest noticeable difference.Technically speaking the pressures should have been checked with other appliances running, but 1mbar is minimal.

 

[dazpoynter]

Thanks for the replies.

Reading at the meter was just over 20 mbar with all the appliances on so all good there I was told.

The fire seems to operate fine and was installed by the correct people just wanted to double check.

 

[muggles]

If it was 20+ at the meter with all appliances running then that definitely sounds like a case of badly undersized pipework. What's the working pressure of the fire at the fire's test point with all other appliances running? If you don't know, this should be found out, if it drops a lot you have a problem

 

[doitall]

If it was 20+ at the meter with all appliances running then that definitely sounds like a case of badly undersized pipework. What's the working pressure of the fire at the fire's test point with all other appliances running? If you don't know, this should be found out, if it drops a lot you have a problem

 

[Razor900]

Not sure a 1mbar drop counts as badly undersized pipework

Sounds fine to me

 

[muggles]

Says when boiler was turned on there was 1 mb drop, implying that the cooker was never lit at the same time as the boiler, so the drop is probably even more. OK so saying 'badly' may have exaggerated a bit but the situation does sound less than ideal

 

[doitall]

If the pressure is 20mbar with the boiler on and 19mbar at the fire, there ain't a problem in my opinion.

But, we don't give gas advice, and it sounds to me as though the OP is playing after the RGI has left, or it's a DIY job.

Therefore any advice is indicative, and has no relation to the actual installation. and should be re-checked by an RGI if the OP isn't happy.

 

[picasso]

could be a big combi on the pipework, installer oversizes the pipework, so fire on 20mb at meter and 20 mb at fire, fire up combi/cooker and you have 1 mb drop across pipework, sounds alright to me.

 

[misterdubya]

Another OP worrying about nowt.

Mr. W.

 

[dazpoynter]

Thanks all for your input,

Just to clear things up testing the working pressure at the fire when it is on as well as the cooker and boiler running it drops to 19, have double checked with the qualified installer and all is fine, was just worrying that I wasn't getting 20 at the fire (which manufacture states) and didn't realise that 19 was not that much of a drop.

Thanks all again.

 

[expertgasman]

Thanks all for your input,

Just to clear things up testing the working pressure at the fire when it is on as well as the cooker and boiler running it drops to 19, have double checked with the qualified installer and all is fine, was just worrying that I wasn't getting 20 at the fire (which manufacture states) and didn't realise that 19 was not that much of a drop. Thanks all again.

The MI's normally say 20 +/- 1. But technically, whatever the meter pressure, there shouldn't be a pressure loss between the meter and appliance inlet greater than 1mb. But to repipe an EXISTING supply becuase it is a bit greater, is a massive pain, and it wouldn't normally happen

 

[Agile]

The reality is that because the tolerances in the pressure at the meter can give 19 mB and with 1 mB loss in the pipework then it can still be correct with 18 mB at the fire.

You are not losing anything and the fire is designed to still be able to work safely with only 14 mB or less so there is no cause for concern.

Without the pressure reading at the meter we dont know the full story about the pipework loss though.

Tony

 

[johnnojob]

gas rate correct ?

no special tools reguired.