Boiler installation questions

[barnes]

Good day.
I would like to put a hydronic heating boiler SIME at my home for hydronic heating. The best place for it is close to my gas water heater (BOSCH). I would like to use the existing gas pipe (which is feeding my water heater with natural gas) to feed the boiler as well. The pipe is 3/4 of an inch. My questions are:
1. Will there be enough natural gas in case the water heater and the boiler will work at the same time (so one device will not slow the other devices performance) using one pipe or should I get a separate line from the gas meter (which is about 15 meters away on the other side of the house)?
2. In case there is enough gas for both devices to work, how much will it cost (roughly) to make a line for the boiler from the existing one about 1,5 meter long with a valve?
3. Can somebody recommend a good gasfitter in the north west of Adelaide for a job like that?
4. Does anybody know where can I obtain information about my gas connection is it high speed or nor? (I have herd that it might be important)
Thank you for your time and help.

 

[breplum]

Are you in Australia?
Greetings from Northern Calfornia!
The gas pressure your local utility provides matters.
Here in Calif., the utility meter drops pressure down to 7 inches water column, which is in the 1/4 lb. psi range.
If you have similar delivered pressure, then roughly speaking, the distance from the meter to the appliance matters.
Around here, no, your existing pipe is not likely to be large enough.

You could consider a "Combi" water and hydronic heating unit in place the Bosch and that would save you a new pipe run. The only brand I would use is Navien, but factory support in your particular area matters, so pick carefully.
Also, I only recommend you use professionals for hydronics, and they will give you the best advice.
Do you have Yelp in your area?

 

[barnes]

Yes, I'm in Adelaide. Thank you for a thorough answer. I have hydronic heating in my other house, but it was a new built and even though I don't have a separate line from the meter and my pipe is also 3/4 inch diameter, everything works just fine. The only difference I have is that my water heater and my boiler are about 40 feet (13,5 meters) apart and they don't share the same pipe between them, even though they are on the same line (only one pipe goes through the house to the meter). But the suburb is different and gas pressure might be different as well.

 

[SHEPLMBR]

And where is Adelaide?

 

[Mitchell-DIY-Guy]

...the utility meter drops pressure down to...the 1/4 lb. psi range.

Things are changing all over. Here in NC, today, the new-home standard is to have the gas pressure at the meter higher. A main line from the meter comes to a manifold, through two regulators. One reduces to 2 psi, the other to 1 psi. High gas usage usage devices (such as a furnace or water heater) feed off the 2 PSI side of the manifold. Smaller usage devices (fireplace, gas grill) feed off the 1 psi side. Each device has its own regulator before the stub off. So, right at the stub off in my garage (which is labeled 2 psi) is a regulator, and the 2 psi is reduced to whatever the water heater itself needs.

This is in stark contrast to the home I built in 1992, where all the gas lines were black iron. 1" coming in the house after the meter, and branch lines ¾" or ½" as necessary. No regulators except what may be built into the meter or the device itself. I have EIGHT gas line pressure regulators visible at my home (crawl space and attic): two on the manifold, two for the furnaces, one each for the fireplace, water heater, dryer, gas grill.

Took me a while to figure this new scheme out, not only the how but the why. The why is simple: builders want to use easy to run soft copper for gas lines now, so with higher pressure they can run smaller pipe. Since it's soft copper they have no fittings or seams except at the beginning and end points. No black iron except for the manifolds and stub-offs.

 

[barnes]

And where is Adelaide?

South Australia, mate.

 

[SHEPLMBR]

South Australia, mate.

I once knew a Mark Barnes that lived in Queensland.

 

[breplum]

Mitchell, that is fascinating about the splitting of loads.
Very nice to have so much flexibility and not have to use large pipes for high gas loads. Rarely in the past, we could get our natural gas provider to boost a house to higher pressure (more readily we got it boosted on commercial). It was always case by case.

 

[Mitchell-DIY-Guy]

Mitchell, that is fascinating about the splitting of loads.
Very nice to have so much flexibility and not have to use large pipes for high gas loads. Rarely in the past, we could get our natural gas provider to boost a house to higher pressure (more readily we got it boosted on commercial). It was always case by case.

The new normal! As a mature experienced plumber you are probably used to only black iron pipe for gas, and one pressure, and no additional regulators. I took a photo yesterday at a new home going up next door to me with a Rinnai tankless so I know what to do in the future...

 

[fixitron]

In the USA the National Fuel Gas Code (NFPA 54) is the standard, and the size of pipe needed is dependent on the gas pressure, the longest run of piping and the BTU/Hr load(s) to supply.