15mm gas supply

[Heating-eng]

what is the best combi to fit on to 15mm ?

 

[Blake]

I would imagine only a 24kw, but even then is still depends on how long the gas run is. Always best to upgrade to 22mm if possible.

 

[Heating-eng]

I would imagine only a 24kw, but even then is still depends on how long the gas run is. Always best to upgrade to 22mm if possible.

Normally always fit 22mm but it is very hard to do on this job.

 

[Blake]

terraced house?

 

[aggis]

You're really going to struggle to get the boilers gas rate on 15mm, unless its very close to the gas meter & no other appliances, remember each elbow reduces the req'd pipe length by 1/2 metre.

 

[Heating-eng]

terraced house?

Yes and its an upstairs flat

You're really going to struggle to get the boilers gas rate on 15mm, unless its very close to the gas meter & no other appliances, remember each elbow reduces the req'd pipe length by 1/2 metre.

To be honest its quite far. i didnt think it could stay on 15mm but just thought i would ask you nice people.

 

[Gray0689]

You have no chance mate needs resized!!

 

[tamz]

Better look around for a 12kw combi then.

This is basic stuff so learn it.
Just because a boiler comes with a 15mm gas connection does not mean you can pipe it in 15mm
No 24kw combi will work on a 15mm supply longer than about 2.5 metres. They all burn around 2.6 cubic metres of gas per hour.
Do a basic pipe size excersise and work it out.

 

[obseen16]

i witnessed an engineer install a 30cdi on 15mm pipe a couple of years ago, i did say something but he said it would be ok. i was only there to fit the rads, oddly enough the customer kept my number and not his, he called me in to service it, the operating pressure was sooooooo low i was suprised it was working at all, think it was something like 15mbar. we resized the pipe for him after i showed him the gauge.

 

[smillsey]

but 15mbar can be ok with a zero governer jobby, they are real good at sucking the smelly stuff into the combustion area

 

[smillsey]

obviouslky the mi's wont say this

 

[kirkgas]

multiply the Heat input by 0.094 which will give you the gas consumption in m3/hr, this will then need to be checked with pipe discharge tables to confirm max pipe run,
eg discharge through 3m of 15mm pipe is 2.9m3/hr
discharge through 6m of 15mm pipe is down to 1.9m3/hr (so will only supply gas to a 20kw appliance)
as said remember to allow an additional 0.5m per elbow, or 0.3m per formed bend,
ie 2m of pipe plus 2 elbows = 3m of pipe
28kw boiler requires 2.632m3/hr so will work properly on a 15mm pipe depending on corrected length (actual length plus 0.5m per elbow) of just over 3m

 

[kirkgas]

i witnessed an engineer install a 30cdi on 15mm pipe a couple of years ago, i did say something but he said it would be ok. i was only there to fit the rads, oddly enough the customer kept my number and not his, he called me in to service it, the operating pressure was sooooooo low i was suprised it was working at all, think it was something like 15mbar. we resized the pipe for him after i showed him the gauge.

do you mean you had 20mb at the meter and 15mb at the appliance?

 

[Heating-eng]

Well i am now updating the gas to 22mm . the nice people in the down stairs flat is letting me run the gas pipe in there lounge.

 

[kirkgas]

Well i am now updating the gas to 22mm . the nice people in the down stairs flat is letting me run the gas pipe in there lounge.

if the gas pipe runs through a property owned by someone else can it be fully inspected and isolated if there is a problem in the future, kinda thinking you cant/shouldn't run a gas pipe through someone elses property

 

[Heating-eng]

if the gas pipe runs through a property owned by someone else can it be fully inspected and isolated if there is a problem in the future, kinda thinking you cant/shouldn't run a gas pipe through someone elses property

The gas meter is outside and this is the only possible way to update the gas.

 

[Gray0689]

The gas meter is outside and this is the only possible way to update the gas.

Can you not run external up the wall??

 

[tamz]

The gas meter is outside and this is the only possible way to update the gas.

Run it up the outside wall.
You are not allowed to run a supply through a different property.

Are you a new start or are you just ripping the pee?

 

[Heating-eng]

Can you not run external up the wall??

Run it up the outside wall.
You are not allowed to run a supply through a different property.

Are you a new start or are you just ripping the pee?

it is a second floor flat ,boiler at front of house and gas meter at back. gas was put in the floor when built.
it is not possible to run gas outside.
not a new starter been doing job for 21 years but was just looking for some advice.

 

[Gray0689]

Looks like you need the kango out lol

 

[Heating-eng]

Looks like you need the kango out lol

It is a real nightmare .i would tell him to get somebody else but i get lots of work from him.

 

[Gray0689]

It is a real nightmare .i would tell him to get somebody else but i get lots of work from him.

Then it's up to you as stated you can't go through the flat bellow you will have to go up the outside of building and in then work the best way in from there (ie cut floor)

 

[Gray0689]

And I'd say at least inch pipe

 

[tamz]

it is a second floor flat ,boiler at front of house and gas meter at back. gas was put in the floor when built.
it is not possible to run gas outside.

There is always a way, just not through another house. Next guy to follow you will shut it off.
Is there a loft or is it a mid floor flat? If there is a loft run it over there.
Is the floor chipboard on block and beam? If so you can lift the boards easy enough.
If concrete floors and no loft you may have to run it high level around the rooms and get it boxed in or as a last resort, run it external around the building.

Blame it on the builder for undersizing the original pipe.

 

[Heating-eng]

There is always a way, just not through another house. Next guy to follow you will shut it off.
Is there a loft or is it a mid floor flat? If there is a loft run it over there.
Is the floor chipboard on block and beam? If so you can lift the boards easy enough.
If concrete floors and no loft you may have to run it high level around the rooms and get it boxed in or as a last resort, run it external around the building.

Blame it on the builder for undersizing the original pipe.

Thank you guys for all your help.