Can I run an indoor gas fireplace off a 20 lb grill tank?
No — that's neither safe nor code-legal. Indoor gas appliances must be hard-piped to an approved outdoor propane supply; code prohibits bringing or using LP cylinders inside a living space. A 20 lb grill tank also can't vaporize enough fuel to feed a fireplace, especially in cold. You need a proper outdoor tank and a licensed gas line.
The code line is bright
Portable propane cylinders — your grill-size 20-pounder — are not allowed to be stored or used inside a home's living area. It's one of the clearest rules in the book, and for good reason: propane is heavier than air, so any leak pools at the floor instead of rising and venting, and a basement or sealed room turns into a hazard. An indoor gas fireplace has to draw from a tank set outside, connected by a permanent, pressure-tested gas line — not a hose to a cylinder you swap in the garage.
Even if code allowed it, the physics don't
A 20 lb cylinder holds only about 4.6 gallons and has a small surface area to vaporize from. A fireplace pulling 25,000 or 30,000 BTU an hour would outrun what that little tank can boil off, particularly on a cold WNC night — the pressure sags, the flame shrinks, and the pilot can drop out. You'd be swapping tanks constantly and still fighting a weak flame. It's the wrong tool for a heating appliance.
What to do instead
If you're on propane out in Candler, Fairview, or up a cabin road, the answer is a stationary outdoor tank sized for the job and a code-compliant line into the house. We run and permit that line, pressure-test it, and meet the county inspector; your propane supplier sets and fills the tank. Grill cylinders belong on the grill — or on a portable outdoor fire pit that's built for them. Call (828) 545-0525 and we'll set it up right.
How we can help
Related questions
- How long will a 20 lb propane tank last on a gas fire pit?
- Can I connect my fire pit to my home's large propane tank instead of a portable cylinder?
- What size propane tank do I need to run a gas fireplace?
- Is it safe to store spare propane cylinders in my garage?
- How long will a 100 lb propane tank run a gas fireplace?
- How do I know if my house has natural gas or propane?
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