w pressure

[SafeGasInstall]

whats the lowest wp at appliance that you/I could install a new boiler ?

 

[Mike Jackson]

1 mbar below that at the meter at the INLET TO THE APPPLIANCE.

 

[SafeGasInstall]

Not so what I remember my self MJ . WB had a bulletin out that there appliances will work safe when wp at appliance was as low as 16 mbar or 13mbar and gas rate was within 10%......
but I will call them Monday (was hopping someone remember it )

 

[Dotty]

1 mbar below that at the meter at the INLET TO THE APPPLIANCE.

I would've taken it as no more than 1mb drop across the pipework, lowest inlet pressure depends on the mi's surely?

 

[diamondgas]

The issue isn't with the appliance you're fitting it's with anything else on the same line ... eg. most cookers specify 20mbar working. if the boilers sucking the WP down to 16mbar then you're spuds are going to take a bit longer to roast! lol

Actually Stan when you're fitting New, technically you've got to guarantee no more than 1mbar across the supply. However, as you state, some mi's will accept lower without it compromising the working performance of the boiler!

As said, main concern I ever have is on how it may affect other appliances.

 

[Whyme]

Pretty sure vaillant have 13mbr as a minimum now at the gas valve. (only the newer version of 831's etc)

 

[Mike Jackson]

Not so what I remember my self MJ . WB had a bulletin out that there appliances will work safe when wp at appliance was as low as 16 mbar or 13mbar and gas rate was within 10%......
but I will call them Monday (was hopping someone remember it )

TB 115

NO more than 2.5 mbar lower at appliance test point than at meter. This allows for a loss of 1.5 mbar across the inlet of the boiler plus 1 across the pipework.

I believe that all condensing boilers must work safely down to 14 mbar but when installing you should comply with the regs. The minimum of 16,5 at the test point is allowing for a the above drops with the minimum working pressure of 19 mbar at the meter. It is not an excuse for leaving an inadequately sized gas pipe in place when fitting a new appliance.

 

[SafeGasInstall]

Trouble is :
paint house in belgravia next to Hampstead in London gas meter is 30m away downstairs in the front of a grate 2 listed building

 

[Ollieg]

Time to rub your hands together and speak to Grovsner estates about it.

 

[Ermintrude]

Well i would say it's going to be expensive ! Either get meter moved or route a 54mm supply. Obviously going to exceed iv on domestic. Upsize meter too. Take u 2 years to get consent from council. 3 years find a parking space

 

[SafeGasInstall]

There is two property's that had new boilers fitted and they had 28mm runs ! One of it is like 20m external and there must have been about 30 90 bends lol
I told customer that will need to calculate how much I can do in 1" 1/4 with about 25 bends and he wants to have a 44kw combi + there is a unknown output gas fire

 

[SafeGasInstall]

I don't think if a run of 1"1/4 will enough to run 50kw gas appliance

 

[Whyme]

even worse if the incoming is below 19mbar and the supplier is happy to leave it at there legal minimum requirement.

 

[Killy Bing]

Grade 2 listed?

hope your public liability covers you..

 

[Killy Bing]

44 kw combi?
insist on a system and invented + hide em

 

[Ollieg]

Put a 25m coil of 2'' yellow under his bed and 28mm to the appliance inlet.
Never see the pressure drop then.

 

[SafeGasInstall]

He had gas tested and there is 26 standing and 23 working at meter with 50000btu boiler + unknown gas fire (no one has gas rated it ) and 13mbar working at gas boiler

 

[Ermintrude]

44 kw combi?
insist on a system and invented + hide em

Invented? U got tickets ?

 

[Ermintrude]

Classy install. What boilers falcons? All those bends may have as well used micro-bore. If external some nice 24" in orca !

 

[Ollieg]

I think i would walk away from this one unless I knew the pay day would be good.
Its alot of red tape and aggro to do this right.

 

[SafeGasInstall]

Exactly what's in my head Ollieg

 

[Ermintrude]

They probably tight and won't pay in full!

 

[SafeGasInstall]

Told him guesstimate gas run will be about £3k ........ he nearly dropped dead on the floor and I asked him does he have a clue how much is 1 x 90 bend ? ( no that I knew my self just playing the game )

 

[Ermintrude]

35mm Yorkshire £16 but retail £45 if you do job get a bender in. ( I'm not available!) or price one into job along with a m18 band saw.

 

[Ollieg]

He lives in Belgravia, wants a 44kw combi, gas meters 30m away and 3k is 2.5k too much for a gas run.

Next week he will get the maserati serviced...