meter to boiler pipe size

[jrmroxx]

Hi, In the near future would like to change standard boiler for either same or combi , meter is at one corner of house and boiler diagonally opposite, pipe starts at 22mm from meter but ends up 15mm at boiler, concrete floors so assuming pipe goes up to and into 1st floor cavity and accross approx 45'.
I am guessing boards will need to be lifted to check where 22 stops. Is there a way of measuring the gas flow to end of 15mm pipe to see if it is enough to fire a combi? Incidently we have a gas fire in living room but very rarely use it at all, 1 main and 1 ensuite 3 bed detached 12 rads total 3 double cheers guys.

 

[Ben-gee]

You just need to get a GSR engineer to come and check it all out, don’t expect it to be free.

 

[jrmroxx]

You just need to get a GSR engineer to come and check it all out, don’t expect it to be free.

Nowt for free these days

 

[jrmroxx]

If your still there Ben have you heard of fitting combi's to 15mm pipe

 

[Scott_D]

If you want a combi that will 2 bathrooms it will have to be a high output model.
A new gas run will be needed

 

[jrmroxx]

Thought as much are we talking 28mm?

 

[Darren Jackson]

There is a way of determining the correct gas pipe size required for your appliance, It is quite a complex equation taking into account a whole load of variables and is the job or responsibility of the Gas Safe Engineer you employ to determine the correct pipe sizing. They may even find that 22mm is not going to deliver the amount of gas required for the combi to operate safely and opt for bigger pipework.
To sum it up, let your GSR decide what is correct.

 

[Darren Jackson]

If your still there Ben have you heard of fitting combi's to 15mm pipe

Generally no with very few limited exceptions.

 

[jrmroxx]

Sounds like a plan.....em a very expensive plan since it involves new pipe line cheers, no holiday for me this year

 

[Sparkgap]

Hi, In the near future would like to change standard boiler for either same or combi , meter is at one corner of house and boiler diagonally opposite, pipe starts at 22mm from meter but ends up 15mm at boiler, concrete floors so assuming pipe goes up to and into 1st floor cavity and accross approx 45'.
I am guessing boards will need to be lifted to check where 22 stops. Is there a way of measuring the gas flow to end of 15mm pipe to see if it is enough to fire a combi? Incidently we have a gas fire in living room but very rarely use it at all, 1 main and 1 ensuite 3 bed detached 12 rads total 3 double cheers guys.

(gets out *** packet) for a typical combi you're looking at about 30kW if you want a half decent hot water flow, compared to whatever (12kW?) for your present boiler. 28mm pipe at least to keep the pressure drop within spec.

 

[jrmroxx]

NO SMOKING while working with Gas.... Thanks Spark gap...or RIP Sparkgap.. Yea so anything in region of 30kw should do the job, cheers for that.

 

[Burger]

As per the others advice, need to be a gas safe registered engineer, as the pipe sizing has changed recently. So to “guess” or even use rule of thumb could result in appliances being under gassed.

 

[Riley]

If you have the option don’t have a combi for two bathrooms

 

[fixitflav]

If you have the option don’t have a combi for two bathrooms

Agree, if he sticks with heat-only, or even a system boiler, unless the output is a fair bit more than the existing (and he's given no reason why it might be) there's a good chance the gas pipe will be OK.

 

[Riley]

It wasn’t based on the existing gaspipe as there are ways around that in terms of where you run it. I was really imploring him not to get a combi boiler if he is going to run two bathrooms as its not up to it

 

[Brambles]

My advice:

Get a trusted plumber in, discuss what you require in terms of heating and hot water and see what he / she recommends.

My personal view ( for two bathrooms ) is to go unvented and system boiler. Others may prefer the Combi route - it often works for large houses with only a couple living there.

I suspect that which ever route you go, the gas supply to the boiler will need to be resized and routed to current regulations anyway.