Working pressure effecting combustion.

[Knappers]

Ok so I called gassafe today to check hoe to clasify low working pressure and was told if it's not effecting combustion then just note it as a fault (ncs) if it is then it's AR.
I've always worked on the principle that when it's close to 14mb or below I'd put it AR and if it was badly effecting combustion ID.
My principle being that possible explosive start-ups and corrosion caused by poor combustion are potentially dangerous and that 14mb is just too low not to take seriously.

Apparently I have no leg to stand on but I still disagree!?

What's your oppinion?

 

[Msjc]

Some boilers can run at as low as 14mb and still work fine without performance issues. All I would do is test its safety and follow manufactures guidance. Take evidence of readings and make note of the issue and present it to the customer letting them know of possible effects.

It could be 14mb when you test it but what happens during high demands, that will lower it even more. Also with other gas appliances running it will lower it even more. I would personally AR it.

I don't agree but what gas safe says goes I guess.

 

[snowhead]

A.R.
It's not going to miraculously get better.
Ultimately it's your call, not Gassafe.

As you are now, if you've found a boiler working at lower than normal pressure it's a judgement whether to leave it on.

However if you went to a boiler someone else had A.R'd with the same 14mb, I think it's most unlikely you, or any other GSR would put it back into service without fixing it.

What's the difference?

 

[Knappers]

On the job that prompted my query the pressure is just over 14mb but it's clearly been piped in 15mm even tho boiler tail is 22mm and really wouldn't be hard to change, it's also one of many rentals that the customer owns so I'm going to stick to my guns this time.

 

[Aire]

14mb working is ok so long as it's maintained with other appliances working and also maintaining 1mb drop accross the installation pipework. Have you tested working at the meter?

 

[Knappers]

1mb across installation I'm not bothered about (I didn't put it in) if it was less than 19 at the meter I'd consider calling transco (or whoever do it now).
It's 22mb dynamic at meter and piped in 15mm.
Granted 14mb is on gas valve so could be as much as 16mb before it, but it's still a crap job that needs putting right IMO

 

[ShaunCorbs]

Ncs for me aslong as it’s running right

 

[Knappers]

Your right I'm sure but would the fact that they replaced the hob burners with random ones from a different hob that rocked around and were clearly dangerous (in a rental property) maybe cause you to be a bit stingy with the rest of the installation too?
Obviously I made that safe...

 

[king of pipes]

This really depends on what you are measuring at the gas meter say if its 20mbar working pressure and 14 mbar at the boiler then the pipework is undersized , if its 18mbar or lower working pressure at the meter I would be getting cadent out to either tweak the regulator or replace it if necessary I personally would not leave 14mbar especially if there are other gas appliances Hob would be ID for me . Kop

 

[Knappers]

I'm with you but it's not what gassafe say.
If it's not impacting on combustion it's 'officially' NCS and even if it is then only AR.
That's with other appliances running (3/4 hob etc)
I was a originally a commercial engineer and certainly wouldn't leave a big forced draught burner running at 14mb, but then you don't get so many cowboys undersizing pipe on commercial