New Capt Cook 4 burner - even on Low it goes through 500 degrees in minutes, and there is hardly any difference in flame size between Hi and Low. what's wrong with it - why can't it stay at a low temp for cooking? Thanks.

https://www.clagrills.com/grillparts/captn-cook/captn-cook-grill-parts-home.htm
https://www.grill-parts.com/bbqparts/captn-cook/captn-cook-grill-parts-main.htm
https://www.thebbqdepot.com/brands/captn-cook/
https://www.appliancefactoryparts.com/gasgrillparts/brands/capt-n-cook/

Not sure what you're grilling, that would require 500 degrees or higher. Unless, you're really trying to char-broil and I do mean char. In any event, it may simply be the thermometer on the hood of your grill, reading incorrectly. Keep in mind, the thermometer is not reading the temp at the cooking grate surface, it's reading the air temperature when the hood is closed.

I do a lot of grilling, I do grill shows for local food stores and I love to grill. But, I have learned to never rely on what the grill thermometer says. I use an oven thermometer that sits off to the side, on top of my grill grates. When I compare the temp on the grill thermometer to the oven thermometer on the cooking grates, there will be a difference of 50 degrees. Now, certainly the temp will drop some, when the hood is opened after preheating. That's normal. But the heat loss, at cooking grate level, is not more than 10 degrees, depending on the outside ambient air temperature. Of course if it's the dead of Winter, the temperature will drop significantly. In that case, grill with the hood closed 90% of the time.

With all of the above said, what do the flames and flame heights look like on each burner? Do they respond as they should when you raise and lower the flames? If not, then you have a gas pressure problem. That can be resolved by turning OFF the tank valve, disconnect the hose from the tank and waiting 5 minutes. Then reconnect the hose to the tank and open the tank valve VERY, VERY, SLOWLY (slow motion, slow). Once the valve is fully open, light the burner farthest from the tank first and turn it to high. Do the flames look higher than they did previously? If so, light the remaining burners following the same procedure as the first burner. Do all the flame heights look correct. If so you solved the problem of low flame height.

I hope all of this has helped you troubleshoot and solve the problem, if there is one. Please let me know. Thanks and Happy Grilling!!

I am guessing this is an LP grill...... it sounds like the regulator has gone bad, purchase a new regulator and hose and put it on the tank...... also, make sure you have gas in the tank.

could be the reg on the tank , not working no flow of gas ,

LP or NG, all burners on high, top closed, out of the high winds (if any) 500+ degrees in 10 - 15 minutes. If not, double check temperture with a secondatry temperture device. If it an old unit, could be gas lines partially cloged. What size of flames come off of the burnes and what are the colors (AT THE BURNER, IN THE MIDDLE OF FLAME, AND AT THE TIP OF THE FLAME.). The olors will indicate the gas / oxyen mixture and therfore heating efficency and templture.)
Yellow is lowest - flame tip light blue almost imvisible is hotest.

The new style OPD valves have a small brass ring located in the female fitting on the LP tank. Over time this ring can work loose and then it does not allow the male fitting to fully depress the OPD valve thus reducing your gas flow
Using a small flat bladed screw driver tighten the small brass ring This should solve your problem

Every one of these ranges that I have seen with the oval style burner on them have a smaller flame then the normal round burners. And there is very little difference between the low and high settings. It sounds like what you are experiencing is normal. What the GE repairman was adjusting is called the "simmer stop". There is a small flat head screw inside the burner stem. By turning this screw you can adjust the size of the burner on the low position of the burner knob. This should be adjusted to where the burner still stays on when the knob is at the lowest setting. I do not think that you need the burner repaired. From my experience they are all like that.

Could it be the draw off the tank is okay for two burners and not 4 hence the temp drop

good day,
hope this link below will solve your problem.

grilling

hellow my name is ash i sale linclion ovens and repair they have only one burner and they only go up to 600 degree F make sure that the impenger plates one on top and one bottem are possion prapley, 2nd set temp at 500 and 530 f time 6.5 m if still under cook blow use plates with holes