Why won't my gas grill stay lit?

Oven clicks as if it is relighting almost constantly.

Old electric range ovens use a coil heating element called a resistive coil.
This is nothing more than an electrical wire encased in a sheath. They have flat black coils over rounded burner drip bowls that catch your drips and spills.
The newer glass-ceramic cook top style element produces heat that radiates through the glass top to the cookware above.

Gas ovens / stovetop that use gas and not electricity. These work by igniting gas and use actual flame on the the stovetop.

Newest cook top styles, such as the induction or halogen cook tops combine the same style to produce more even heating. Some of these ovens feature thermal limiters or thermostats that regulate the burner system.

GAS OVENS
The spark igniter tip is dirty (can clean it with either a little wire brush or a piece of fine sandpaper).
2) The Pilot flame is too low, and the tip of the igniter is not in the flame good enough. (the flame acts as a circuit when it touches the tip & completes the circuit).
3) The spark module is no good and needs to be replaced.(But 1 & 2 are your best bet).
spark module does not sense the flame when it's on. The spark igniter is also the flame sensor which provides feedback to the spark module.

Make sure the igniter is properly aligned with the burner lighting holes and it is clean. All lighting holes must be clean too. You can enlarge them using a drill bit one size bigger.

If it would not fix the problem, replace the bake burner and the igniter.
There is a small chance for the spark module itself to be bad as well.

The oven safety valve
(also called the gas valve) is the part that ensures that gas is not released until the igniter has reached the correct temperature needed to ignite the gas. While this part can fail, it is uncommon. If the hot surface igniter does not glow you should first verify that you have voltage to the circuit. This is a live voltage check and should be performed by a qualified person. If voltage is lost at the valve terminals then you should verify the continuity of the bi-metal in the valve using a multi-meter.


ELECTRIC OVENS:

CHECK THE OVEN RELAY CONTROL BOARD Aclicking sound could be something wrong with a relay. Check for any loose connections around the main control board on your oven. The click you hear is a relay losing power and switching back on. If the clock resets then something is causing power interruptions to the board.