Hello everyone! I am a certified gas fitter and I have been working in the barbecue repair industry for about 5 years now. As you all know, the Weber Q grill is extremely popular, both for portability for camping, etc., and for size in small condos. Far too often I hear people complain that their Weber Qs aren't getting hot enough, or that the barbecue used to work great but now it doesn't. On occasion it's the regulator, or sometimes a dirty burtner, but in almost every case the person is using an adapter hose with a 5/10/20lb propane tank, not the disposable 1lb canister that the Weber Q is designed to run on. I decided to write up a guide for my website on how to fix this issue and I figured it would be a good idea to spread the word so people can stop swearing at their barbecues and get back to grilling!
Why won't my Weber Q work?
In my career as a gas fitter and barbecue salesman I have encountered literally thousands of people that have issues with their Weber Q grill not getting hot enough, or perhaps not lighting at all. Sometimes it is a bad regulator, or sometimes they haven't cleaned their burner, but by far the single biggest cause is the use of an unregulated propane adapter hose. This hose combined with the "OPD" safety device in a modern tank can cause issues with insuffient or no flow of gas.
What is an OPD?
Modern propane tanks sold in North America are equipped with a safety device called an OPD. OPD stands for Overfill Protection Device, and in very basic terms it could be described as a hollow ball in a cage at the end of a tube. It's primary function is to prevent propane tanks from being filled past 80% capacity, which provides the space necessary for propane to turn from liquid to vapor. When the propane liquid level reaches the ball, it raises and blocks off the flow of gas from the tank. A secondary function of the OPD is to shut down or reduce the flow of gas in the event of a signifcant depressurization of the propane hose, such as would happen if the propane hose were severed.
This is what an OPD most commonly looks like, though there are other types. (Image taken from
http://www.rv.net/forum/index.cfm/fuseaction/thread/tid/26283959/gotomsg/26289078.cfm)
Why is this happening if the hose isn't severed?
In most cases the OPD is triggered because of the initial flow of gas into the adapter hose which triggers the OPD, combined with insufficient wait time to allow the pressures in the tank and the hose to equalize. If the barbecue is lit too soon after turning on the tank, the hose never pressurises and so the OPD ball never drops to allow full flow of gas. In most cases the equalization of pressures takes less than a second, however when using an adapter hose this can take much longer because the high pressure gas (150+ PSI!) rushing down several feet of hose triggers the OPD long before the hose has a chance to fully pressurize.
But my barbecue works for a while then stops, what gives??
When using an unregulated adapter hose, even if the OPD triggers prematurely there is still sufficient pressue in the hose to run a low demand appliance for several seconds to several minutes. A standard Propane (LP) appliance runs at 11" WC (Watercolumn). 1 PSI is equal to 27.68" WC, so a propane appliance runs at less than half of a PSI, thus if the hose contains even 50 psi it can still contains enough gas to run a low BTU appliance for a while.
So what's the solution?
Unfortunately there isn't really a solution to the problem, because the problem is using an unregulated adapter hose. However the problem can be completely prevented by using the appliance the way it was intended to be used;
with a 1lb disposable propane canister. If the disposable canister option is too expensive, inconveinient, or wasteful for you, then you can use the following method to convert your barbecue to run only on propane tanks with a standard OPD fitting on them. Keep in mind that you will no longer be able to use disposable propane canisters without purchasing an adapter!
WARNING: Propane gas can be EXTREMELY dangerous. If you are at all unsure of your ability to perform the following modifications please contact a licensed gas fitter to perform the modification for you. I cannot be held responsible for any damages to property or injuries sustained from gas leaks or improper installation of parts during the following procedure!
Required parts:
1 x 3/8 Male flare to 1/8 Female pipe thread fitting (I use Fairview Fittings part # 46-6A)
1 x Barbecue hose and regulator, Any length with do.
Gas tape or pipe thread sealant
Wrenches
1. Disconnect any hoses and tanks from barbecue.
2. Remove cooking grill and burner from barbecue. Burner is held down with a 7/16" nut and bolt, or a 3/8" bolt.
3. Pull off control knob and remove brass lock ring from gas valve with an adjustable wrench. Remove valve and regulator from barbecue. Newer models have a black bracket that can make removal difficult.
4. Remove valve from regulator. Inspect for oil buildup in valve. Excessive oil build up will require replacement of valve.
5. Apply gas tape or pipe sealant to threads of the gase valve. Do not get any tape or sealant in the valve that could obstruct the flow of gas.
6. Screw 3/8FFL x 1/8MPT fitting onto valve and tighten. DO NOT over tighten, the brass threads can strip.
7. Attach hose and regulator to fitting on valve. No gas tape or pipe sealant is necessary on flare fittings. Snug flare nut hand tight and give it an extra 1/4 turn.
8. Insert gas valve back into barbecue, tighten lock ring. Reinstall control knob and burner. Do not install cooking grills yet.
9. Ensure gas valve is in the OFF position. Brush or spray a solution of 50/50 dishsoap and water on each connection and fitting. Connect regulator to propane tank and open tank valve. Look for bubbles at all connections. Retighten connections if necessary.
10. Observe flame on high and low. There should be a distict difference between high and low settings. Clear any obstructions in burner ports with a straightened paperclip.
Hopefully this helps a few people that are having difficulty with their Weber Qs! Feel free to ask whatever questions you may have and I'll try to answer them.
