A propane regulator controls the amount of propane that reaches a burner in an oven or grill. Since these are placed directly under the burners, it's not uncommon to have problems with them occasionally. If your burners aren't heating up as you think they should, there are some simple things you can do to find and correct the problem.
Look for Obstructions
Food that is allowed to drip on to the actual burner can eventually clog the regulator. For outdoor grills, leaves and other grime can cause the same problem. Simply inspecting the burners can alert you to this being an issue. You can avoid these issues by purchasing a cover for off season. Using spill guards on pans for a stove, or just making sure that you are using proper sized pans can also eliminate these issues.
Check the Vent Holes
Another reason the burners may not be heating up could be a clog in the vent holes. To check for this you just need to tap on the unit until the tubing moves. If there is any debris in the vent holes it should come loose with the tapping. A can of air can also do the trick if the tapping isn't working. Make sure the gas supply is off before you do this. Most cans of air are under pressure, and using this while the propane is still on can be very dangerous.
Check for Damage
A damaged hose can cause problems with the burners. If you smell propane, you should immediately stop using the unit. Weak spots in the hose can cause propane to leak. You can check for weak spots and holes by removing the hose and submerging it in to a bucket of soapy water.
If you see bubbles, then you have a leak. While there are patch kits available, it's much safer to just toss the old hose and purchase a new one rather than try to repair the damaged one. If you don't see bubbles, then run your bare hand along the length of the hose. You want to feel for differences in the thickness of the tubing. A soft or otherwise soggy spot indicates a weakened section, and the hose should be replaced.
A propane tank can make strange noises when there is a problem with the tank. You may think there is a problem with the regulator, when in fact the tank is the culprit. Listen for gurgling or humming sounds coming from the regulator. If you hear this you may have a tank that is overfilled.
A tank that is too full can actually limit the flow to the burner. You can't drain propane out of a tank that is too full. If you are working with a portable tank you should just carefully return it to the retailer and get a new one. For a large permanent propane tank, contact your propane supplier to alleviate the issue. You should not attempt to release propane on your own.