Gas supply for Vaillant 937 / Copper or Plastic

[smurfy125]

I wonder if anyone can help me???
I have chosen a new Vaillant 937 boiler to go up into my loft and was told to run 2 X 28mm pipes to the boiler for the gas supply. I cant understand why i would have to do this as the gas meter has a 22mm connection and so does the boiler. I did read somewhere that if the boiler is over 3 metres away from the gas supply use a 28mm pipe but 2 ???????.

Also whilst trying to sort this problem out i am in a dilemma on using plastic piping for the water and central heating or copper. Any advice would be greatly appreciated. Thanks!!

 

[Agile]

One would hope that you will be getting a CORGI to fit the gas supply and the essential CORGI parts of the boiler installation, mounting bracket, flue, gas connection and commissioning.

The suggestion for two 28 mm pipes in parallel is because the boiler uses a lot of gas and the gas supply at the boiler has to present a minimum gas presure at the boiler inlet. Its irrelevant what connection sizes the meter and boiler fittings are. In any case the meter connections should be 28 mm.

Its your choice what you use for the heating and water circuits. Most professionals prefer copper! Some have strong views on which is best!

Tony

 

[BigBurner]

One would hope that you will be getting a CORGI to fit the gas supply and the essential CORGI parts of the boiler installation, mounting bracket, flue, gas connection and commissioning.

If he is doing it himself he does not need to be CORGI registered.

The suggestion for two 28 mm pipes in parallel is because the boiler uses a lot of gas

Tony

This is madness. This boiler does not need two 28mm pipe for the gas gas supply.

 

[BigBurner]

I wonder if anyone can help me???
I have chosen a new Vaillant 937 boiler to go up into my loft and was told to run 2 X 28mm pipes to the boiler for the gas supply. I cant understand why i would have to do this as the gas meter has a 22mm connection and so does the boiler. I did read somewhere that if the boiler is over 3 metres away from the gas supply use a 28mm pipe but 2 ???????.

Also whilst trying to sort this problem out i am in a dilemma on using plastic piping for the water and central heating or copper. Any advice would be greatly appreciated. Thanks!!

How far away is the boiler from the meter? The gas meter can have a 1" x 28mm connector fitted.

Plastic is OK for the water and CH. It would go for copper to be safe.

The 937 consumes 4.2 cu metres per hour of gas. You can work it out from this:

http://www.cda.org.uk/megab2/build/pub124/sec3.htm

 

[Agile]

This is madness. This boiler does not need two 28mm pipe for the gas gas supply.

Without knowing the distance from the meter to the boiler in the loft then how can you know what pipe size is required?

Have you surveyed the gas supply route?

Tony

 

[Agile]

If he is doing it himself he does not need to be CORGI registered.

But he DOES need to be competent to work with gas!

As he does not know how to size gas pipes.......

Tony

 

[BigBurner]

If he is doing it himself he does not need to be CORGI registered.

But he DOES need to be competent to work with gas!

As he does not know how to size gas pipes.......

Tony

30 metres of 28mm copper pipe will deliver 4.7 cu metres per hour of gas at the end of it. He will need one hell of a large house to double up 28mm pipe.

 

[BigBurner]

If he is doing it himself he does not need to be CORGI registered.

But he DOES need to be competent to work with gas!

He is asking questions so appears competent enough.

As he does not know how to size gas pipes.......

Tony

Neither do you.

 

[Nixt]

He is asking questions so appears competent enough.

Familiar looking comment. BigBurner, would you, by any chance, be connected with Doctor Drivel, Water Systems, Balenza (TBC) or Richard Hanson-Granville?

 

[Agile]

30 metres of 28mm copper pipe will deliver 4.7 cu metres per hour of gas at the end of it. He will need one hell of a large house to double up 28mm pipe.

I agree, but I have not seen his house and perhaps it isa one hell of a large house!

It also sounds as if he has been advised on needing the two 28 mm pipes by someone who is CORGI registered and has visited the property.

Tony

 

[Agile]

As he does not know how to size gas pipes.......

Tony

Neither do you.

Well I have passed the ACS and CORGI seem happy with my ability to size gas pipes!

And more relevant is that when I fit supply pipes they usually deliver gas on full load with a pressure loss within the BS recommendation of < 1 mB .

Tony

 

[BigBurner]

As he does not know how to size gas pipes.......

Tony

Neither do you.

Well I have passed the ACS and CORGI seem happy with my ability to size gas pipes!

That doesn't say much for ACS and CORGI then, as you are lacking in this department.

 

[BigBurner]

He is asking questions so appears competent enough.

Familiar looking comment. BigBurner, would you, by any chance, be connected with Doctor Drivel, Water Systems, Balenza (TBC) or Richard Hanson-Granville?

I know of Balenza and Doctor Drivel from doing searches. Alas no relation to any of them.

 

[doitall]

Competent or not, Why would he need 2 x 28mm pipes over 30m pipe run is very unusual in a domestic.

Perhaps one is for the pressure relief valve.

 

[smurfy125]

I have an ACS Gas Certificate which i have held for the last 6 years with renewing it of course. But i do not install boilers for a living, i am a sparky by trade that has been trained to ACS but not corgi registered, i just dont do gas enough to be up to date with experience, which is why i am asking because i was told to run 2X 28mm gas pipe to the boiler which is approx 10 to 12 metres away from the gas supply.
I am asking the question because i could noy understand what i would gain from it.
You see i am running all the pipe work and then getting it all connected by a registered fitter.