So, I have a Weber two-burner gas grill that has given me great service for at least the past 10-12 years. However, recently, it has developed a 'bad habit.'

When I crank the heat past 50%, the whole thing just catches fire. See photo:



At first, I thought this was just years of grease/fat build-up catching fire on the inside of the grill. However, I scraped the entire insides down just this year (I had a lot of free time on my hands for some reason), and the problem persists. In the past 10 years, it never did this. I cannot cook ANYTHING on high heat without the entire grill catching fire and scorching all my food.

I then suspected that the burners are leaking or something. Naturally, a gas leak with open flame is a bad thing.

Any thoughts?

looks like a faulty burner or connection hose/fitting between the control knob and the burner.

Make sure you don't have grease build up on the bottom

Your burner tubes could be split. A new two-tube set plus a crossover tube might be $45. They are a little tricky to install but not impossible. Last week I removed the tubes from a Weber Genesis 'Silver' grill, which is a c.2005 two burner model. The crossover tube was clogged and corroded. We cleaned everything up and it burns more evenly and with higher heat but my brother will probably try to get a crossover tube from Weber.

The two connections to the (2) burner valve orifices are outside the grill body, under that right-hand shelf.

The burner tube kit is similar or identical to this. With a picture like that, if you are the original owner, Weber might send them out no-charge:

https://www.weber.com/US/en/ac...ment-parts/7507.html

Yeah there is something going on with the gas tubes. Should be lots of tiny little flames. It even looks like it is following the path of the tubes so yeah, maybe they are split or the regulator is bad or a combo.

As stated above I have also rebuilt my silver of 15+ years. Tubes and regulator. Not really expensive if the rest of the grill is in working order and easy to do.

Thanks, everybody, for the advice.

This place never ceases to amaze me.

If your Weber grill has "flavor bars" take them out and inspect them for burn through holes. Just a thought.
Edit:
I just re-looked at your picture, and of course your grill has the bars.

Yep I replaced the burners and flavor bars on my old one and it ran like new. Parents still use that one years later. Weber’s can be fixed much cheaper than buying a new one and parts are available at any big box store, or the internet.