Will Your Gas Meter Support a Whole-House Generator?
Standard residential natural gas meters are rated for 250 cubic feet per hour (CFH), which equals 250,000 BTUs. Adding a 10kW to 12kW tri-fuel generator (180,000 BTUs) to a house with a gas furnace and water heater requires upgrading to a 400 CFH meter.
01 How to Read Your Gas Meter Faceplate Rating
Walk outside to your gas meter and locate the metal specification plate. Look for a class designation such as Class 250, AC-250, or AL-425.
The number indicates the meter flow capacity in cubic feet per hour (CFH) at 0.5-inch water column differential pressure. One CFH of natural gas contains roughly 1,000 BTUs of energy.
NFPA 54 requires flexible fuel lines to deliver full engine demand with under 0.5 inches Water Column pressure loss. Generators drawing over 85,000 BTU/hr demand minimum 3/4-inch hoses.
- A 250 CFH meter supplies 250,000 total BTUs per hour.
- A 400 CFH meter supplies 400,000 total BTUs per hour.
- Operating above rated CFH causes gas pressure to sag throughout the house.
02 Calculating Total Connected Household BTU Demand
To determine if your meter is adequate, sum the maximum nameplate BTU input ratings of all connected natural gas appliances in your home.
Consult our typical appliance demand table below, or use our interactive Natural Gas Pipe Sizer.
| Household Gas Appliance | Typical BTU Input Rating | CFH Consumption | Meter Share % (250 CFH) |
|---|---|---|---|
| Gas Central Furnace (80k) | 80,000 BTU/hr | 80 CFH | 32% |
| Tankless Water Heater | 199,000 BTU/hr | 199 CFH | 80% (Overload Alone) |
| Standard Tank Water Heater | 40,000 BTU/hr | 40 CFH | 16% |
| Gas Range & Oven | 45,000 BTU/hr | 45 CFH | 18% |
| 10kW Tri-Fuel Generator | 160,000 BTU/hr | 160 CFH | 64% |
NFPA 54 requires flexible fuel lines to deliver full engine demand with under 0.5 inches Water Column pressure loss. Generators drawing over 85,000 BTU/hr demand minimum 3/4-inch hoses.
03 Requesting a Utility Meter Upgrade
Most gas utility companies (CenterPoint, Atmos, Nicor, ConEd) will upgrade a 250 CFH meter to a 400 CFH meter for little to no cost to encourage gas usage.
Call your utility before hurricane or winter storm season, as meter upgrade work orders typically take three to six weeks to schedule.
NFPA 54 requires flexible fuel lines to deliver full engine demand with under 0.5 inches Water Column pressure loss. Generators drawing over 85,000 BTU/hr demand minimum 3/4-inch hoses.
- 1 Photograph Meter Badge: Take clear photos of the meter badge, regulator, and customer account badge.
- 2 Submit Total BTU Tally: Provide the utility service rep with your exact total appliance BTU total.
- 3 Verify Delivery Pressure: Confirm standard 7 inches water column (4 ounces PSI) delivery pressure.
- 250 CFH meters support 250,000 BTUs; 10kW generators need 160,000 BTUs.
- Homes with gas furnaces and tankless water heaters require a 400 CFH meter.
- Gas utilities typically perform meter upgrades for minimal or zero cost.
Frequently Asked Questions
Q: What happens if my generator draws more gas than my meter allows?
The gas regulator will starve appliances, causing furnace burners to produce carbon monoxide and the generator engine to stall under load.
Q: Can I run my generator if I have a 250 CFH meter?
Yes, if you manage appliance usage: ensure your central furnace and water heater do not fire simultaneously while the generator is running.
Q: What is 7 inches water column in PSI?
Seven inches water column equals approximately 0.25 pounds per square inch (PSI), the standard low-pressure delivery for residential appliances.