Gas cooktop question

[cda]

I am possibly looking at changing an electric cooktop to gas cooktop

I already have gas to the house for water heater and gas central heat

What problems are there to do this???

I will have to extend the existing gas pipe

Do not have a specific cooktop picked out

But looks like most require 5inch water column minimum

I guess it takes a plumber to test how much pressure is in the line?

Also some spec either 1/2 inch or 3/4 inch line and not sure what size the existing is, but will check

I keep hearing about is the existing pipe big enough to handle all three appliances, not sure if this is a valid concern??

Thanks for any info

 

[jar546]

You will need specifics on the type of gas you are using.

You will need specifics on the Btu requirement of the appliance

You will need to know the sizing, length and Btu draw of your existing appliance situation

You will probably want to convince yourself a permit is not needed for this. Consult with local contractors who can give you lots of reasons why you won't.

 

[cda]

Natural gas

Yes permit will be involved.

Have seen to may gas leak fires in attics

Also I do want a leak test done

Thanks for the draw answer

 

[north star]

% % % %

cda,

Good points from Jeff!

What are your plans to vent this appliance to the exterior? ...venting

thru the roof, or the side wall? Vent termination location, ...distances

away from other combustible materials, ...distance away from air

intakes in to the structure, yadda, ...yadda, ..yadda!

Also, since you opened the door, we will want pictures of the project.

We abuse, ...eeeeeeerrrrrrrr, "critique" our own ya know!

% % % %

 

[cda]

Clearance is no problem wife wants granite counter top an fancy tile backsplash

There is a vent a hood on place that is vented to outside already

More then likely will up grade it also

 

[north star]

* * * *

That "faint-see" tile back splash could be really difficult

for you to clean, if you're installing the travertine type

tile.......It's much too porous!

Besides, we would not want you in there slaving away

for hours on end cleaning behind the Mega Cooktop 9000.

* * * *

 

[Jobsaver]

What problems are there to do this???

It most likely will not be a problem to add a cooktop to an existing gas piping system that is only carrying a water heater and furnace, but until you do the math, it is hard to say for sure. What is needed to size the system is some basic information concerning the existing piping and appliances. How far is it from the meter to the farthest appliance? What is the btu input rating of the farthest appliance? Same questions for the second appliance? Last, what are the current lengths and diameters of gas piping that comprise your system?

Measure the pipes, then draw a simple schematic giving lengths and diameters. The btu input ratings will be listed on the appliances, but are somewhat standard for many home appliances. 40 gallon tank type water heaters, for example, may use 40,000 btu, but a tankless may use 200,000 btu. A typical gas furnace will use about 20,000 btu per system "ton", ie: a four ton system furnace will usually have an 80,000 btu input. : 100,000 btu for a furnace matched to a five ton condensor, etc.

Break....

 

[mtlogcabin]

Leak test can be done a couple of ways. I would suggest doing the entire system. Shut off the supply and all existing appliance shut off valves. Install a fitting with the proper gauge and a schrader valve pump it up to the required test pressure for your area and wait. 15 minutes should be enough but i know contractors who will leave the test presure on for hours. IF it bleeds down get out the soap water. DON'T FORGET TO RE-LIGHT THE PILOT LIGHTS IN THE EXISTING APPLIANCES.

 

[JBI]

All of the above. Should not be a big deal, at most increasing the size of the existing line. Have you asked your gas purveyor for guidance?

PS - This is a fuel gas question... not plumbing. D'OH

 

[cda]

Oh no need to ad another category "residental fuel gas""

Great advice thanks all

Now have to get up in attic and take some measurements

 

[Glennman CBO]

Your gas supplier should be able to tell you the water column pressure. I have never installed a gas appliance in a home that didn't already match up to what the home already had (as long as the type of gas is the same, LP vs Nat).

The unit will come with a regulator that will need to be installed.

Also, be careful on testing the old piping. You can actually cause a leak somewhere in a wall that will need to be destroyed to fix it.

I would only test the new piping. Depends on how old the existing system is. I've tested old piping due to additions onto the system, and found my self in trouble trying to locate the leaks in the walls that didn't leak until I pressurized it. Remember that 5 in water column is only approx 1/4 lb of pressure. A 15 lb test is about 60 times more pressure than the system is under. If all the old piping is accessible, then no problem, but be ready with the pipe wrenches.

I'm not saying that all old systems are fragile. I'm only sharing my 20 years in gas pipe fitting experience, 75 percent of it adding to existing systems. I wouldn't be afraid to pump up any system to 5 lbs, but if you don't isolate the new piping from the old, you will need to test the entire system anyway, to whatever pressure the jurisdiction likes to see.

 

[Daddy-0-]

If your service pipe is too small you could do an elevated pressure system and then step the pressure back at each appliance with individual regulators. Gas pipe size is the most important thing in cases like these. The best advice is to hire a good, reputable and licensed contractor and get a permit. Some of those gas ranges can draw HUGE amounts of gas. I inspected an 85,000 btu version yesterday that was run with 1/2" copper gas pipe. Not gonna work people.