gas supply pipe to combi
 

I have been told that the 15 mm gas supply pipe to my 8 year old
Vaillant TurboMax vuw 242E should be 20 mm .

Is this correct?

The installation manual only states a minimum of 15 mm.

tia

I have been told that the 15 mm gas supply pipe to my 8 year old
Vaillant TurboMax vuw 242E should be 20 mm .

It is more complicated than that and depends on the exact routing and
lengths. However, 22mm would be more likely to be required in most
circumstances.

Christian.

"bilge" wrote in message
...
I have been told that the 15 mm gas supply pipe to my 8 year old Vaillant
TurboMax vuw 242E should be 20 mm .

Is this correct?

The installation manual only states a minimum of 15 mm.

tia

It depends on the maximum gas requirements of all your appliances and the
diameter, lengths and bends of all your pipework.
There is info on how to calculate it here - (Adobe PDF Document)
http://www.ukcopperboard.co.uk/downl...&%20sizing.pdf
It is important to get it right because if there is not enough gas pressure
available - then an appliance may produce deadly carbon monoxide fumes.
I think it is a good idea to upgrade the pipework to 22mm anyway.

Dave

logized wrote:
"bilge" wrote in message
...

I have been told that the 15 mm gas supply pipe to my 8 year old Vaillant
TurboMax vuw 242E should be 20 mm .

Is this correct?

The installation manual only states a minimum of 15 mm.

tia


It depends on the maximum gas requirements of all your appliances and the
diameter, lengths and bends of all your pipework.
There is info on how to calculate it here - (Adobe PDF Document)
http://www.ukcopperboard.co.uk/downl...&%20sizing.pdf
It is important to get it right because if there is not enough gas pressure
available - then an appliance may produce deadly carbon monoxide fumes.
I think it is a good idea to upgrade the pipework to 22mm anyway.

Dave



thanks for advice and info

On Wed, 24 Nov 2004 10:11:34 +0000, bilge wrote:

I have been told that the 15 mm gas supply pipe to my 8 year old
Vaillant TurboMax vuw 242E should be 20 mm .

Is this correct?

No, it should (almost certainly) be 22mm .

The installation manual only states a minimum of 15 mm.
And the minimum is presumably not good enough here.
See FAQ.

--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html

bilge wrote:
I have been told that the 15 mm gas supply pipe to my 8 year old
Vaillant TurboMax vuw 242E should be 20 mm .

Is this correct?

The installation manual only states a minimum of 15 mm.

The rule of thumb is 22mm from the meter most of the way to the boiler,
with up to 1 metre of 15mm to the boiler itself if necessary.
However thumbs are all different sizes :-)

If the run from the meter to the boiler is very long (over 20 metres)
and/or the boiler is very big (over 28kW) some of the pipework may need
to be in 28mm. However the maximum permissible lengths for given flow
rates depend on something like the 4th power (i.e. squared and squared
again) of the pipe size, so 3m of 15mm pipe is equivalent to perhaps
100m or so of 28mm; in other words even a fairly modest length of 15mm
will impose an unacceptable pressure drop in the pipework.