What this worksheet is for
Sizing a gas line starts with knowing the total demand: the input rating of every appliance that could run at the same time. Homeowners can gather most of that information themselves by reading rating plates, which saves time during a plumber's visit and makes estimates more accurate.
This is not a sizing calculation. Pipe sizing depends on length, material, pressure and code tables that a licensed plumber applies. Your job here is to provide a complete list.
How to find each rating
- Locate the rating plate.It is a metal or paper label on the appliance, often inside a lower access panel, on the back, or inside the door frame.
- Find the input.Look for 'input' with a number followed by BTU/h or BTU per hour. Some list a maximum and minimum; record the maximum.
- Do not open sealed panels.If the plate is behind a panel that needs tools, leave it for the plumber.
- Add planned appliances.Use the spec sheet for anything you plan to buy, such as a tankless unit or fire pit burner.
Appliance worksheet
| Appliance | Location | Input (BTU/h) | Approx. age | Existing or planned |
|---|---|---|---|---|
| Water heater | ||||
| Furnace | ||||
| Range or cooktop | ||||
| Oven (if separate) | ||||
| Dryer | ||||
| Fireplace or insert | ||||
| Pool heater | ||||
| Spa heater | ||||
| BBQ or outdoor kitchen | ||||
| Fire pit or fire table | ||||
| Generator | ||||
| Total |
Also note for the plumber
- Rough distance from the meter to the farthest appliance
- Where the main gas pipe enters the house
- Any appliances added since the house was built
- Symptoms such as weak flames when several appliances run
- Whether any line runs underground to the yard or pool pad
- Photos of rating plates you could not read clearly
Terms on the rating plate
- Input
- How much gas energy the appliance burns per hour at full fire.
- BTU/h
- British thermal units per hour; the unit for input ratings.
- Natural gas / LP
- Fuel the appliance is set up for. Make sure it says natural gas for a utility connection.
- Manifold pressure
- A setting for technicians; not needed for this worksheet.
Common questions
Can I size the pipe myself from the total?
The total is only one input. Length, material, pressure and code tables also matter, so leave sizing to a licensed plumber.
What if I cannot find a rating plate?
Note the make and model number; the plumber can look up the input. Do not remove sealed panels.
Do I list appliances that rarely run?
Yes. Sizing assumes appliances could run at the same time, so include everything.
General information for Villa Park, not a quote or professional advice. In an emergency, call 911.