So, you’ve just fired up your barbecue, except... wait a second... it hasn’t quite fired up fully. Maybe there’s a touch less heat than you usually feel, or maybe the flame doesn’t quite look like it used to. These are some of the clues that can indicate you have a problem with the flow of fuel into your barbecue. Luckily, there are only a couple things that can cause this and they’re all relatively simple solutions, whether your barbecue runs on natural gas or propane, we’re going to dive in and get you back to grilling!
Safety Valve (For Propane-Fueled Barbecues)
The most common cause of a reduction in heat to the barbecue is peculiar to liquid propane grills, for some time now (though you may remember a time before) it has been required that all propane tanks 40 lbs and under have an overfill protection device (OPD) fitted to them. What the OPD valve does is restrict the flow of propane out of the tank if it detects too much at once, and also stops the tank from being overfilled. It is essentially a safety valve, and while it’s something that we don’t usually notice (because it works), it sometimes works too well and this is when it becomes, not an issue per se, but certainly a nuisance, especially if you’re unaware of it. Sometimes, whether you’re overzealous to get grilling or running outside in the winter to preheat the barbecue (or as said unaware of the OPD valve in the first place) you may twist the knob too fast. This action of turning the knob on the propane tank too quickly is enough to set off some OPD valves and restrict the flow of liquid gas coming out of the tank. This is one cause the barbecue is not getting hot enough, because it won’t cut off the flow of fuel completely. The solution for this is easy; all you have to do is turn the knob on the propane tank off, unscrew the propane regulator from the tank and then reattach it (this is more for posterity than anything). Here comes the tricky part: turn the knob on the propane tank very slowly, and once you’ve turned it all the way, it never hurts to turn it back a touch as well. You should have full flow into the grill now, instead of the decreased flow triggered by the OPD valve. This is a funny issue because it can never happen to a tank and then happen suddenly, and also because few people even know about it at all. If this has corrected your issue and your barbecue is once again grilling at full capacity, you’re free to go, but if not, the issue is at least isolated to being within the barbecue itself.
Possible Gas Leak
If you have a natural gas barbecue and are experiencing a reduction in the heat it’s producing, the first two things to do are; check if you smell gas, and check for leaks. Using your nose is easy, but to check for leaks, you’ll want to use our pro-grade Masters Leak Detector fluid on all of the joints along your natural gas connection (from the barbecue all the way to natural gas hookup).
If you see bubbles form where you have put the leak detector, that means you’ve got a gas leak and it also means you should reaffirm that natural gas connection. All that you need to do this is a couple wrenches to unscrew (and screw-back) the connection, gas fitters tape or pipe sealant, and your leak detector to check it again once you’ve pieced it back together. Remove the old tape or sealant from the connection, and attach a new amount; keep tension on the tape while you apply it so that it molds to the threads of the connection uniformly. If you’re using sealant, apply just enough to cover the threads, there is no need to lather it on excessively. Screw it back together and leak check the connection again, if there are no more bubbles, hooray! This is the one time in your life you should be happy not to see bubbles. Unlike liquid propane equipped barbecues, there is nothing similar to the OPD valve system that restricts the flow of fuel at the source if there is an irregularity detected. Therefore, if your barbecue still isn't getting up to temperature, move on to diagnosing the issue within the barbecue itself.
If you've deduced that the issue isn't arising from the gas supply line, then the issue is probably coming from within the barbecue itself. A few things could indicate there's an issue with your burners:
- one side of the grill is hotter than the other
- the flame colour changes suddenly and dramatically
- there is a popping sound coming from the barbecue
Now, the inside of your barbecue can be a daunting thing (especially if you don’t regularly clean it), but luckily, barbecues are designed to have their parts easily replaced. This is in part to increase the longevity of the sturdy enclosure surrounding the innards, but also because all that heat and the drippings from the food you cook do eventually take a toll on the parts inside (even with sturdy stainless steel). Thankfully because of these factors, they always disassemble easily.
The most common blockage is within the venturi. The venturi is a narrow section, usually at the front of the burner, where the flow of fuel is temporarily constricted before being expulsed into the burner tube and turned into the flame.
Upside-down burner shows venturi with spider mesh
Before getting to the burner, you’ll have to make sure the barbecue is completely turned off at the fuel source so that absolutely no fuel is flowing into it (you can even switch on the knobs for a few minutes and then turn them off after unhooking it to release any remaining fuel), easy enough. Next, remove the grill grates and flavour bars. Now that the burners are visible in all their glory, you’re probably asking, “what kind of horror could obstruct the burners of my precious barbecue?” And the reality is that the most common cause is spiders, or some other small insect that would like to make a nest in a tight space. These insects are particularly attracted to the smell of gas, so your barbecue makes for quite an attractive home to them. That’s why even with a new barbecue this can be a common issue, the same as with the OPD valve.
The easiest way to clear this unwelcomed arachnid obstruction is with a venturi tube brush, simply insert it into the open end of the burner (the side that does not have the mounting attachment) and start sweeping, back and forth, up and down, left and right, clear it out. Any obstruction should fall away with a vertical turn of the burner after you’ve given it a good scrubbing, or will stick to the brush itself. Reaffix the burner(s) in place, reinsert the other parts that were removed, and you should be back up to heat and ready to cook.
Another thing to look out for is the burner itself being clogged with grease, rust, food, or anything else. Give whole burner a good scrub and shake to ensure this refuse isn't causing your blockage issue.
If the problem persists after cleaning your venturis and burner, the issue won't be something that can be fixed by simply cranking up the heat on the barbecue. Doing so is a dangerous idea and could potentially be a recipe for disaster - not the kind of recipes you want to be cooking up with your grill!
If you’ve cleaned out your burners, affirmed that the issue is not from within the supply line, and you're still experiencing a reduced level of heat from the barbecue, it is possible (although unlikely) for the orifice to be obstructed or damaged. It is also paramount to ensure that you’re not using a natural gas barbecue with a propane tank or vice versa. We know this seems quite intuitive, but it doesn't hurt to double check!
To check the orifices, return the grill to the state it was in when you had the burners removed. Now, the orifice will be directly in front of where you just removed the burner from, close to the knob on the manifold. You won’t have to remove the orifice to clean it, but use the same brush you used to clean the venturi. The orifice will be a much tighter squeeze so don’t worry if you can’t fit the brush inside of it. Reassemble the grill, and try again!
If you’re STILL having issues, or have any questions about the processes that we’ve covered here, send us a message on our website, give us a call, or swing by one of our five locations across Canada. We have two in Calgary and three in the GTA in Ontario located in Burlington, Oakville and Etobicoke. Our team of barbecue experts are always happy to answer any questions you may have!