Size of gas feed pipe for a regular condensing boiler?

[quatro]

I've been told that if I change my boiler to a combi boiler the gas feed pipe needs to be changed to a larger diameter one.
But if I change to a regular condensing boiler would this still need to be changed?
[It runs under the floorboards of the bathroom, hall and kitchen so changing it would cause major disruption].

Or could a new pipe be fed into the bungalow via the loft and run down to the boiler?
Thanks...........

 

[arfurrrr]

it is true, new boilers (combi) require correct pipe sizing to ensure its safe function and operation , this could be 22mm , 28mm or 35mm , dependant on distance from meter , other appliances etc .

the existing supply maybe ok , for a sytem boiler , but it also may not .


arf

 

[EliteHeat]

35mm? that would be some boiler, or, maybe a boiler in the next town!

 

[doitall]

35mm? that would be some boiler, or, maybe a boiler in the next town!

The 2 boilers I have just installed needed 2" (50mm) 65kw each

 

[EliteHeat]

35mm? that would be some boiler, or, maybe a boiler in the next town!

The 2 boilers I have just installed needed 2" (50mm) 65kw each

Not a two-up, two-down then?

 

[doitall]

35mm? that would be some boiler, or, maybe a boiler in the next town!

The 2 boilers I have just installed needed 2" (50mm) 65kw each

Not a two-up, two-down then?

No, one up, none down quite high ceiling though, around 45 feet

 

[2face]

never done over 28 mm .. above this is classed as commercial sounds like a tall story to me !!

 

[arfurrrr]

2face , check the gas regs domestic installer can install 35mm pipe .

 

[HarrogateGas]

2face , check the gas regs domestic installer can install 35mm pipe .

But not a 65kw boiler...let alone 2.

 

[2face]

iam sure over 28 is classed as commercial ..

 

[HarrogateGas]

So a 38kw Gloworm combi is commercial..............i think not. A 30KW Ideal Isar is commercial.........i think not.

 

[doitall]

iam sure over 28 is classed as commercial ..

Nope you can go up to 35mm now on a domestic ticket.

I can go up to 1m³ volume.

 

[arfurrrr]

thanks DIA.

2face , read details infull as there are new rules on purging and tighness testing .

arf

 

[Biggles..]

2face , check the gas regs domestic installer can install 35mm pipe .

But not a 65kw boiler...let alone 2.

I think you'll find a domestic installer can fit upto a 70KW boiler.

 

[fitz1]

i fitted some 54mm 2 yr ago. awwww . sssshhhhhhh.