Size of gas pipe for new boiler (Ed.)

[richardmm]

hi I'm getting new boiler install combi to remove the old cylinders but pipe is 15 and engineer say he needs to upgrade supply to 22 so is it needed???????

 

[richardmm]

the floor is concrete so mean he will have to dig up floor which is vinyl so not interested invor

 

[Jurassicspark]

hi I'm getting new boiler install combi to remove the old cylinders but pipe is 15 and engineer say he needs to upgrade supply to 22 so is it needed???????

Stealing old threads is against the forum rules.

Regarding your post, you'll need to run the 22mm gas pipe to your boiler. It will not perform well with the current 15mm one.

Can't the engineer not run the pipe another way?

 

[CountryFan]

hi I'm getting new boiler install combi to remove the old cylinders but pipe is 15 and engineer say he needs to upgrade supply to 22 so is it needed???????

If it’s been pipe sized correctly and he says it’s needed, then chances are it’s needed.

 

[CountryFan]

the floor is concrete so mean he will have to dig up floor which is vinyl so not interested invor

Not entirely sure what this means. As suggested, it might be able to be run a different route.

 

[fixitflav]

hi I'm getting new boiler install combi to remove the old cylinders but pipe is 15 and engineer say he needs to upgrade supply to 22 so is it needed???????

Ditch the idea of a combi and the issue goes away.

 

[richardmm]

Not entirely sure what this means. As suggested, it might be able to be run a different route.

i will ask the enginer to see what he say but thank you

 

[richardmm]

fixitflav what you mean? childish behavior

 

[bernardgreen]

.

avoids taking up flooring and/or cutting large notches in joists

 

[fixitflav]

fixitflav what you mean? childish behavior

Tell me what you're getting at with "childish behaviour" and I'll tell you what I mean

 

[richardmm]

Tell me what you're getting at with "childish behaviour" and I'll tell you what I mean

when i say for advice give good advice but you said rude way to ditch the new boiler

 

[vulcancontinental]

Before you can say ditch the combi keep the old pipe it would be useful to know the output of the proposed system or heat only boiler the combi would be ditched for. System and heat only tend to be higher outputs, 20kW's possibly and the pipe needs to be sized for the boiler input irrespective of combi or system and just because before was OK the installer is responsible for the new installation complying with regs.

 

[Harry Bloomfield]

Almost without fail, a swap from heat-only, to a combi boiler, will involve an upgraded supply pipe. It is not optional, it is a requirement. You choices are to accept the install of a new larger pipe, or replace your heat-only with another heat-only boiler, which would not be in itself, a bad choice, depending. The depending, is what condition is the rest of your system in - the cylinder, pipework, and loft tanks etc.. If parts of that need replacing then, it might prove to be the much more expensive option.

 

[fixitflav]

when i say for advice give good advice but you said rude way to ditch the new boiler

It wasn't meant to be rude, you asked for advice and mine is keep the existing system and renew the boiler, unless there are other considerations like state of the cylinder etc, which we don't know about.
Combis have their place, but on this forum at least, more posters are against combis than for them.

 

[fixitflav]

System and heat only tend to be higher outputs

I don't know where you get that from. Combis tend to be 28 - 34kW, vs heat-only typically 15kW.
According to my calc if the existing is 15 kW, 15mm pipe up to 8m length is within the allowed 1mb loss, but of course it's up to the OP's installer to advise.