The burners flame is the same on my Q100 Weber Grill whether it's on high or low. I tried new cannisters and hook it via mainline to my RV tank. No changes in the flame.

Clean out the burners and the injectors on the gas line to each burner .

try cleaning the burner and the orffice first

Don't worry, you'll be grilling in no time, if you follow these instructions:

1. Turn the gas tank valve OFF.

2. Disconnect the grill's hose from the propane tank and wait 5 minutes.

3. Reconnect the hose to the tank and open the tank's gas valve VERY, VERY SLOWLY (Slow Motion, slow).

Once the valve is fully open light one burner and turn it to HIGH. Has the flame height returned to normal? If so, light the remaining burner and turn it to HIGH. Do both flame heights look normal?
If so, you solve the problem! Remember to always turn the tank valve ON Very, Very Slowly.

Hope this helped you. Please let me know and Happy Grilling!!

turn off the LP Tank, disconnect the hose from the tank and wait 5 minutes. Reconnect the hose and turn the tanl valve on very, very slowly, until it's fully open. Light each burner and turn it to high. Wait for the burners to heat up and turn them down gradually to low. If flame height on low has returned to normal, the problem is solved.

If that didn't solve the problem, the air shutters on each burner may need adjusting. Consult the installation instructions that came with the new burners for the proper setting or consult your Owners Manual.

If it's real real cold outside, it's not unusual for the burners set on low to have a problem. The only solution to that is let the grill preheat well, before turning the burners down. Also, grill with the hood closed on low, if it's a windy day.

Hope this helps you and gets you back to grilling again.

Nope, the regulator is not the problem. It's the LP tank regulator. The new OPD heads on the tanks are designed to prevent over filling. All 20lb cyclinders now have them. But, it's easy to solve.

Turn off the tank, disconnect the s/regulator from the tank, wait 5 minutes. Then reattach the hose/regulator to the tank and turn the tank on very, very slowly, until it is completely open. Now, try lighting the burners one at a time and turn them up to high. That should have solved your problem, by allowing the regulator to reset itself.

Just remember to always turn the tank on very, very slowly after turning the tank valve off each time.

Regulator is not bad, as I stated before new valves are designed to reduce gas flow if valve is opened to fast. This is so if grill catches on fire, the tank will shut itself off, thus propane will stop flowing causing fire to extinguish itself.

turn tank off disconnect from grill make sure all knobs are turned off including side burner reconnect tank make sure fitting is all the way on tank turn tank on and try again

Remove the burner and check the flexible tubes for kinks or blockages. The flexible tubes usually just slip over the backs of the valves. Spiders love to get in there and block them. Also check that the holes in the burners are not clogged. Be careful when reseating the flexible tubes to be sure that they are properly seated on the back of the valves. Failure to properly seat the flexible tubes can cause leakage there, and the gas can ignite at the back of the valves and not reach the burner. Be certain that the replacement burner is designed to use with your grill and the flexible tubes mate properly with the back of the valves.

I had this problem with a brand new grill so it wasn't grease in the hose. Due to the new propane regulators you have to turn the propane tank on for at least a minute before turning the grill to light. Let the tank sit in the light position for five seconds and then you light the grill. This will keep air from getting into the intake hose and will keep your gas flame roaring high.

I was only able to get the grill up to 250 degrees before I found this fix posted on the Weber site. It is listed as the number one solution in the FAQ section.

The only way you can fix the low flame, low heat problem, is to remove the grill, take a medium sized paper-clip (staightened out) and clean out each individual hole on the steel burner, flame tube. (I'm sure there's a technical name for it).

Since they (the holes on the flame tube) face up unprotected, directly under the grill cooking surface they tend to get blocked quickly with continous use and certain foods, like pork ribs. Bad design unless all you plan on grilling is hot dogs.

There are about 500 individual holes, so plan on being there a while. Or in other words, do it close to the cooler.

I've been tempted to toss the thing into the woods a bunch of times over the past 2 years I've owned the dumb thing.

Good luck!