New combi (poor gas supply)

[Wayned]

Hi looking for a combi boiler that can use 15mm mains gas as my meter is 100ft away from boiler and combi I got is 15mm gas pipe from meter

 

[Corgigrouch GTi]

Looks like you'll have to have a new gas supply from the meter to the boiler then..

 

[Dan Robinson]

Even the smallest combi will be needing 28mm most of the way

 

[Iamchamps]

I don't think many will allow that. When I had my new boiler fitted it used the 15mm but the gas supply is about a meter away (other side of wall) I was told if much further the pipe would of had to of been 22mm.

edit; before anyone points it out yes the manufacturer instructions state 22mm. However I saw the test results and everything was perfectly in spec so I was happy to keep the 15mm. Even a gas safe employee who came out to do an inspection after the installer said it was fine.

 

[bernardgreen]

Why are you committed to having a combi ? A much smaller heat only condensing boiler and a hot water storage cyclinder could be more efficient (*) than a combi and may be able to run on the existing gas supply.

(*) over all efficiency ( amount of hot water produced and used against volume of gas used ) and not the mathmatically manipulated "efficiencies" quoted by manufacturers that are based on "tests" that bear very little comparison to actual use of the boiler in a domestic situation. ( some are more than 100% efficient )

 

[Wayned]

Over 100ft apart So near the cost of a boiler

 

[Wayned]

Heard ideal had a combi running on 15mm. Is this true

 

[Dan Robinson]

It's got nothing to do with the manufacturer.

A 24kw boiler (the smallest combi) will need 28mm most of the way regardless of who made it.

Do shut up Blowhardgreen.

 

[Corgigrouch GTi]

Heard ideal had a combi running on 15mm. Is this true

Lots of boilers have 15mm gas inlets but that means Jack. it is about the pressure drop in the pipework... Perhaps your Gas Safe installer could help you better.

 

[bernardgreen]

Do shut up Blowhardgreen.

Explain why a smaller boiler and hot water cylinder could not provide adequate heating and hot water.

 

[Corgigrouch GTi]

Explain why a smaller boiler and hot water cylinder could not provide adequate heating and hot water.

So what size boiler can the OP run on a 15mm gas supply roughly 100 ft in length with indeterminate bends and elbows and an unknown number of other gas appliances each with an unknown input requirement?

 

[Mottie]

So what size boiler can the OP run on a 15mm gas supply roughly 100 ft in length with indeterminate bends and elbows and an unknown number of other gas appliances each with an unknown input requirement?

The one he has already?

 

[Corgigrouch GTi]

The one he has already?

Well, we don't know if the existing boiler was installed correctly. And so it may have its own issues.

 

[AGAS]

The one he has already?

why does that make a difference . jeez I've got that saying ringing in my ears , " its alright its always been like that"

 

[Mottie]

Well, we don't know if the existing boiler was installed correctly. And so it may have its own issues.

You're right, we don't know, so until we do we can only guess hence the question mark at the end of my comment.