Grills and outdoor
Gas grill low flame: what bypass mode is
- 4 sources
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Quick answer
A propane grill with a weak, low flame even on high is often in "bypass." Weber says that since around 1995, every Weber propane hose and regulator has a federally mandated safety device designed to detect gas leaks. If the grill isn't lit in a very specific way, the device acts as if there's a leak and cuts gas flow to about 10% or less, so the grill can't reach normal temperature, or may not light at all.
Hose or regulator damaged? Weber's kit (check the fits list for your grill):
Weber 7501 Hose and Regulator KitWeber's kit page says to check the fits info to choose the right part, and its support team (800-446-1071) can help.
What sets it off
A Weber LP owner's manual says all burner knobs must be OFF before you open the tank valve. If a knob is on when gas starts flowing, the flow limiting device built into the regulator activates. Weber's blog adds that cold weather delays the pressure equalizing, so give it extra time when it's cold.
The reset, short version
- Do a leak test first.
- Open the lid and turn every knob OFF, including the side burner.
- Open the tank valve and wait several seconds for pressure to build. Weber calls this the most important step.
- Light the grill per your manual, light all burners on high, and close the lid.
Weber says a grill that's working right should reach about 500–550°F in 10–15 minutes with the lid closed. Full steps: how to reset a grill regulator.
Guides in this section
Leak check first. Weber says do a leak test before anything else, never check for leaks with a flame, and never use a grill if a leak is present.
How we work: details come from Weber's bypass article, its propane tank article and a Weber LP owner's manual. We don't test grills ourselves. Follow your own grill's manual. Sources are listed below.
Questions people ask
What is bypass mode on a gas grill?
Weber says a safety device in the hose and regulator cuts gas flow to about 10% or less if the grill isn't lit in a very specific way, so it can't get hot.
What causes bypass?
A Weber LP manual says the flow limiting device activates if a burner knob is on when you open the tank valve. Keep all knobs off first.
How hot should my gas grill get?
Weber says with all burners on high and the lid closed, it should reach about 500 to 550°F in 10 to 15 minutes.
Sources
Last checked Oct 23, 2026. Details come from Weber's bypass and propane tank articles and a Weber LP owner's manual. Never use a grill with a gas leak.