Troubleshooting Low Heat or Weak Flame on Weber Gas Grills

Low temp condition in Weber gas grill

You fire-up your Weber gas grill and it’s not coming up to temp like it normally does and the flames don’t look right. Here are the things you should be looking at to troubleshoot and solve this problem.

Check The Fuel Level

If the heat and flame pattern in your grill seem low and you’ve got a propane grill, your first instinct is probably to check the fuel level of the tank. That’s a good start…maybe it’s time for a propane tank refill.

Clean Or Replace The Burners

Remove the cooking grates and Flavorizer bars and check the condition of the burners. They may be clogged with cooking debris or corrosion. The burner holes can usually be cleaned and cleared and returned to good working order. In the worst case scenario, the burners may need to be replaced. You should also check the spider screens to make sure nothing is blocking them.

The Gas Regulator Has Gone Into Bypass Mode

If you’ve got plenty of fuel and clean burners but the heat and flames still aren’t right, then it’s possible your grill has gone into what Weber refers to as “bypass mode”. This occurs when the regulator—that aluminum contraption at the end of the gas hose that screws onto the tank—detects a gas leak…or at least thinks there’s a gas leak.

Every time you open the propane tank valve, the regulator compares the difference in pressure between the gas in the tank and the gas in the hose leading to the burners. When the pressure equalizes on both sides, the regulator allows gas to flow freely to the grill when you open one of the burner control knobs.

However, if the regulator senses that the pressure in the hose is lower than the pressure in the tank, it trips a safety device known as a bypass that reduces the flow of gas to a faction of the normal flow, under the assumption that there may be a leak in the system. The flames will burn very low and the grill won’t get very hot, perhaps no more than 250°F.

Did You Accidentally Put Your Grill Into Bypass?

You can accidentally put your grill into bypass when you have a burner control knob open before you open the tank valve. That’s a no-no. You should always make sure that all burner control knobs are closed before opening the tank valve fully. Allow a few seconds for the gas pressure in the regulator to equalize, then open a burner control knob and light the grill. (You did read the lighting instructions for your grill in the Owner’s Manual, didn’t you?)

How To Reset The Regulator When In Bypass

If you think your grill is in bypass mode, you can reset the regulator by following these steps:

  1. Turn off all the burners and close the tank valve.
  2. Wait 60 seconds.
  3. Open the tank valve fully and wait a few seconds for pressure in the regulator and gas hose to equalize.
  4. Open the grill lid, then open one of the burner control knobs and light the grill.
  5. Turn all burners to HIGH and close the lid.

The flames should be strong and the grill should heat to over 500°F in 10-15 minutes.

If this process does not work, try it again, but in Step 2 disconnect the regulator from the propane tank and wait 60 seconds before reconnecting it and proceeding to Step 3.

Maybe You’ve Got A Gas Leak Or Bad Regulator

If you’re lighting your grill correctly and it keeps going into bypass mode, you may have a gas leak. To check for leaks, open the tank valve fully but keep all control knobs in the OFF position. Apply a soapy water solution to the hose and all gas connections using a brush or spray bottle. Bubbles will appear at the point of any leak. Repair any leaks and retest using soapy water to confirm the fix.

If you can’t identify any leaks, then you may have a bad regulator. Contact Weber Customer Service at 800-446-1071 for help.

Weber Video On Regulator Bypass

Weber’s got a nice video on the subject of regulator bypass, hosted by our friend Kevin Kolman.