I have a HUGE Hibachi grill (it's basically a mattress-sized metal slab over multiple heating conduits) in my restaurant to cook burgers, cheesesteaks, grill fish, etc.

This morning, I turned it on and left it for about 30 minutes (to warm up), and when I came back, it wasn't as warm as it should be. I checked underneath to see what the issue was, and the fire was very weak. I set it at 300 degrees (which I usually set it at), but the heating element were lit in a few places, and some not. I cranked it all the way up to 500 degrees, and the "fires" were lit to about the size it would be when I used to have it at 300.

Another issue was that one of the pilots (there are 5) was not lit. Using a lighter, I lit it, and it was a VERY small light, not like the other 4.

So I used the other part of the grill, as it was working fine. Later during the day, I tried to turn on the malfunctioning side, and it worked just fine.

What seems to be the issue here? I checked the pipes, and they all seem to be fine as the other side of the grill is working just fine.

Check gas pressure coming into building

Check gas pressure ay equipment

Post back you might have a pressure regulator.

Are you on natural gas? OR propane

Are all the other gas appliances working?

Natural gas.

The thing is, the other part of the same grill is working just fine, and they're all running on the same line.

All other gas appliances (fryers) are working just fine.

The orifices could be restricted (dirt,grease,spidew web) The only way to tell is to start looking.

Ah, I figured.

... this would mean I have to take it apart somehow... which means I have to somehow lift it up to look underneath it (it's based on top of a table)... which means I have to find a way to lift it... and somehow look into the pipes...

Well hvac, you've somehow confirmed my assumptions. Only thing to do now is to figure out how to fix it.

Thanks.

If your appliance has a regulator then look around for a "vent". It's just a tiny hole on the outlet side of the regulator. If that vent gets plugged then your gas pressure will drop off substantially. From my experience, in restaurants these vents can and will get blocked with grease/grim.