outdoor-grills-101

Gas Grill Ignition Systems

Fri, 18 Oct 2013 17:08:30 +0100

There have been several attempts through out the history of gas grill manufacturing to produce a reliable automatic ignition system. Starting out with the simple Piezo Electric igniters and concluding with Hot Surface igniters. In this article, we will take a look at the pros and cons of each system and what can go wrong to make them stop working.

The majority of ignition systems on grills work using a spark to ignite the gas coming from the burner in order to light the burner. The necessary components are a "spark" generator, wiring to carry the spark, and an electrode that allows the spark to "jump" from the tip of the electrode to a ground point. How easily the grill lights and how long the ignitiion system lasts depends on how good all three of these components are.

Piezo Electric ignition systems were the industries first attempt to produce an automatic ignition system. Piezo Electric spark generators are still in use, but they are not the best spark generators available. The picture below shows two examples of Piezo Electric spark generators.

Piezo spark generators come in the push button or rotary style. The push button spark generator has one wire terminal on the bottom that connects to a wire running to the electrode. Sometimes the push button spark generator has a second wire terminal below the push button that connects to a wire running to a side burner or a ground wire running to the electrode. The rotary spark generator can have up to 4 wiring terminals each with a wire running to an electrode.

When you push the button or turn the knob on a Piezo spark generator you will hear a "snap". As you bush the button or turn the knob, a spring is compressed and a hammer is pulled back and released. The hammer strikes a quartz crystal and produces and electrical "charge" that runs down the wire to the electrode. The spark is not particularly hot, and if there is any deterioration in the wiring, corrosion of the electrode or mounting bracket, the spark becomes weaker and often unreliable.

In my experience, the push button spark generators seem to last the longest. The rotary spark generators fail when the black cap (bottom picture opposite side of the cylinder from the wire terminal) pops off due to fatigue and the parts inside the cylinder come out. Your Piezo spark generator has failed when you no longer hear the "snap" when you push the button, or the knob on the rotary style spins loosely.

Replacement involves simply removing the old spark generator, installing a new one, and re-connecting the wiring. This sometimes requires the removal of the front panel from the grill. This is also a good time to check the wiring and electrodes to make sure there is not more than one problem with the ignition system. When you install the new spark generator it is important to install one with the same number of wiring terminals. If there are more terminals than wires, then a ground wire will have to be installed to ground the open terminal or the spark generator will not work properly.

Battery operated ignition systems were the next to appear on outdoor grills. Battery operated system have the advantage of a repeated spark, a more reliable spark, and a hotter spark. Battery operated igniters use transformers to increase the voltage of the battery to produce a hotter spark.

Below are pictures of a AA and AAA spark generators..

The large, square portion of these spark generators is typically behind the control panel and the cap with the rubber boot is visible. The cap acts as the switch, pushing on the cap activates the spark generator. The cap is removed to replace the battery. The AA spark generators can also have a cap without the rubber boot and a separate switch is used to activate the spark generators.

AA spark generators can have as many as 6 outlets, and some may have switch terminals as well as wiring terminals. AAA spark generators can have up to 4 wiring terminals and do not have switch terminals.

Below are pictures of 9V spark generators.

9V spark generators are always completely concealed, usually behind the control panel, and are activated by a separate switch that is wired to the switch terminals. The battery is under the cap of the spark generator on the left and slides into the slot on the right hand side of the spark generator on the right. Normally the battery can be changed by reaching under the control panel to access the battery compartment of the spark generator. Some times the grease tray will need to be removed. The 9V spark generator on the left comes in a 2 terminal and a 4 terminal model and multiple spark generators and switches are used on larger grills. The 9V spark generator on the right can have as many as 6 terminals.

If the battery operated ignition system is working properly, the snapping of the sparks will be heard as long as the cap or switch is held down. The most common failure is a dead battery, replacement of the battery is the first thing to try. If the battery has been allowed to corrode inside the spark generator, the spark generator will need to be replaced. If a new battery does not fix the problem, then it may be failure of the spark generator itself, a wiring problem, an electrode problem, or a combination of problems. Troubleshooting will have to be done to determine exactly what is working and what is not. When replacing the spark generator, the replacement should have the same number of wire terminals as the original. Unused, open terminals on the spark generator must be grounded for the spark generator to work properly.

As well as the spark generator, ignition systems have wires and electrodes. In some grills, only one burner is lit with the ignition system so there will only be the spark generator, a single wire, sometimes a ground wire, and a single electrode on one main burner. The remainder of the burners are lit using cross over tubes between the burners. On more complicated ignition systems, each main burner and rear burner will have its on wire and electrode. On some grill models, depending on the total number of burners, there may be multiple spark generators as well.

Below are examples of electrodes and wires.

All electrodes will have the electrode itself, a white insulator, and a mounting bracket. Some electrodes have attached wires and some have separate wires. The thicker and heavier the electrode material, the better the insulator, and the better the wire is heat insulated, the longer the electrode and wiring will last.

The electrode and wire on the left is typical of those found in inexpensive Chinese Import grills, note the thin electrode and thin insulation on the wire. These type of electrodes and wires tend to fail fairly quickly. These types of electrodes often use the burner itself for the ground point and the spark to ignite the gas will jump from the tip of the electrode to the burner.

The electrode on the right is from a higher quality grill. The electrode is heavier and the insulation on the wire is much better. This electrode also has a ground post, the spark jumps from the electrode to the ground post to ignite the gas. This is a much more efficient system as the gap between the electrode and the ground post is easier to adjust, and maintain, than the gap between the electrode and the burner. This type of electrode and wire typically costs more to replace, but lasts for years.

The electrode has to ground to the fire box in order to work properly. This is accomplished through the mounting bracket and is attached to the fire box with a bolt or screw. The heavier the mounting bracket, the longer it will last and the better the ground will be.

Some electrodes mount to a hood/collector box that is attached to the fire box creating a ground point. Below are pictures of some typical hoods/collector boxes.

The electrode will be attached to the hood/collector box at the mounting point with a bolt or screw. The tip of the electrode will be inside the hood/collector box and the spark will jump from the tip of the electrode to the hood/collector box to ignite the gas and light the burner.

The hood/collector box provides some degree or protection for the electrode and helps to trap gas around the electrode making it easier for the spark to ignite the gas to light the burner. As always, the thicker and heavier the hood/collector box is, the better ground it will provide and the longer it will last.

Typical failures of the wiring are cracks, breaks, or melting of the insulation caused by age or damage from overheating. This allows the spark to jump to ground before it reaches the tip of the electrode short circuiting the system. The wire itself will also age and become less conductive over time. Sometimes the insulation can be repaired, or the wiring will need to be replaced. If the wire is part of the electrode assembly, then the electrode and wire are replaced.

A crack or break in the insulator of the electrode will also allow the spark to jump to ground and short circuit the system. Replacement of the electrode fixes the problem. The mounting bracket of the electrode can also corrode preventing the electrode to ground properly, or completely break off allowing the electrode to move away from the ground point preventing the spark from igniting the gas to light the burner.

If a wire or electrode needs to be replaced, it is always recommended to replace the wire, electrode, and hood/collector box at the same time. If you are going to replace one electrode, wire, and hood, it is also a good idea to replace them all as failure of the remaining electrodes, wires, and hoods will not be far behind.

Flame Thrower ignition systems are the combination of a Piezo spark generator and the main burner valve itself. Below is a picture of a Flame Thrower ignition.

These type of ignition systems are primarily found on less expensive Chinese import grills. When the burner knob is pushed in, a jet of gas comes out of the flame thrower gas jet, and moves up the delivery tube. When the burner knob is turned, the hammer of the Piezo spark generator is pulled back and released creating an electrical current that travels through the wire to the tip of the electrode. The spark jumps from the tip of the electrode igniting the gas coming out of the delivery tube and a jet of flame, hence the name flame thrower, shoots along the side of the burner igniting the gas in the burner and lighting the burner. All of the Flamer Thrower ignition and valve sit behind the control panel and are not visible without removing the control panel.

Typical failures include the failure of the Piezo spark generator, damage to the insulation of the electrode wire, and damage to the white electrode insulator. Since the Flame Thrower ignition is part of the valve itself, the only remedy to the typical problems is to replace the entire valve as component parts are not available. This is major work, and care must be taken to avoid a leak when replacing the valve. This should be done by a qualified professional.

The most common problem, and what I believe to be a design flaw, which could result in a back flash fire behind the control panel creating more problems is the clogging of the Flame Thrower gas jet and/or the delivery tube. I find this most often in grills that are not used very often, and grills that set unused over an entire summer.

The Flame Thrower gas jet has a very tiny orifice that can become plugged or partially plugged with dirt, etc. This will either completely stop the flow of gas, or worse, partially stop the flow of gas causing the gas to flow out behind the control panel instead of into the delivery tube. The delivery tube is the perfect home for spiders and insects to build nests. Insect or spiders nests inside the delivery tube will force the gas to flow out behind the control panel instead of the end of the delivery tube. Repeated attempts to light the burner will result in an increasing amount of gas buildup behind the control panel. If the spark from the electrode ignites the gas built up behind the control panel, a back flash fire will result that will melt parts of the valve and burn up the electrode wire resulting in the need to replace the entire valve. I see this on a regular basis with Flame Thrower type ignitions.

Hot Surface ignition systems are usually only found on high end outdoor grills. Below is a picture of a hot surface igniter.

Hot surface igniters are similar to the "glow" plugs used to light gas ovens in the kitchen. When the knob on the grill is pushed in, a micro switch sends an electrical current through the wiring and the element at the end of the igniter. The element begins to heat up and glow. When the element reaches the correct temperature, it ignites the gas coming from the burner and lights the burner.

Early hot surface ignition systems had very fine heating elements and worked on very low voltages such as 3.5 volts. These systems were unreliable as any drop in voltage anywhere in the system would allow the element to glow, but not get hot enough to ignite the gas from the burner. Newer systems us the heavy igniters pictured above and 12 V to provide a reliable system.

Typical failures are the micro switch on the valve, damage to the wiring, or failure of the element. Since these systems involve lots of wiring behind the front control panel, repairs should be left to professionals.

Gas Grill Components - Burners and Grates

Fri, 27 Aug 2010 17:27:53 +0100

In my last segment, I discussed the fire box on which all of the other grill components are mounted. In this segment I will cover burners and the grates/flame tamers that are on top of the burners.

Burners come in all sizes and shapes, to many to cover in this article, so I will just discuss the different materials that burners are made out of and the pros and cons of each.

Cast Iron - Cast iron burners have been around for a long time. Cast iron burners are still being used in a lot of grills today. One advantage of cast iron is that the burner heats up and holds the heat. The thicker the casting of the burner, the more heat it holds. Cast iron burners can also be less expensive than burners made out of other materials. The major drawback to cast iron burners is that cast iron rusts and corrodes faster than other materials. This rust and corrosion results in the narrowing, and eventually the closing of the gas ports that produce the cooking flame. I have also seen cast iron burners warp and deform over time. This is especially true with the thinner cast iron burners found on the Chinese import grills. If you grill you are considering has cast iron burners, check the thickness of the cast iron burner, the thicker the material the less chance it will warp or deform, and the longer it will take to rust and corrode.

Brass - Brass burners are found on some grills instead of the cast iron. In many cases the shape, size, etc of the brass burner is identical to cast iron burners. Brass burners share the same heat holding characteristics as cast iron, but do not rust or corrode as fast and are more resistant to warping and deforming. Brass will cost more than cast iron.

Stainless Steel - Stainless steel burners will not hold heat like the cast iron and brass burners will. This means when you open the lid of your grill the temperature drops more rapidly than with a cast iron or brass burner. Stainlees steel burners will take much longer to corrode than cast iron or brass, but they will eventually corrode and wear out. How long the corrosion process takes, depends on what type of stainless steel is used in the burner. As with any other stainless steel component on a grill, it should be heavy guage, 304 stainless. The better the grade of stainless steel, the longer it will last. Check the warranty on the grill, and the burner if it has one, the longer the warranty the better quality of the parts. Chef's Choice and Pro Fire grills, for example, have a life time warranty on all of their stainless steel burners.

The newest type of burner is the "infrared burner". Infrared burners do not cook by direct flame, like a conventional burner, but instead have a ceramic grid with small holes covering the acutal burner. This allows the heat to move up and cook the food. These burners get extremely hot in a very short period of time when compared to conventional burners. These burners were originally created to "sear" the surface of food to hold in juices, the food was then moved to a convential burner for cooking to temperature. Early infrared burners had only one heat setting, high. Infrared burners also have the advantage of vaporizing grease and dripping that fall on to their surface, creating smoke that flavors the food, and keeps the infrared burner clean.

Newer infrared burners now have a wider range of temperature control. This allows a wider variety of foods to be cooked over an infrared burner. Infrared burners heat up in 3 to 5 minutes and cook very quickly. This means shorter cooking times, but also means that food can be overcooked, or burned, very quickly. It takes a little practice before you get it right, and ruining your fisrt meal, or two, is not unusual.

Infrared burners are often included with convential burners inside of one grill. Some grills have one or two infrared burners and the rest are conventional. This provides the best of both worlds, as a wider variety of food, and more temperature control is available.

The simplest grate/flame tamer is made out of sheet metal and sits directly cover the burners. They do a good job of protecting the burners, but not of dispersing heat evenly throughout the grill. They also wear out quickly becuase they will rust, corrode, and warp faster than other materials.

Some grates are simple "wire" grates that consist of rods welded together in intervals at a 90 degree angle. The thickness of the rods, usally 1/8" to 5/16", determines how long before heat and corrosion wear them out. These grates have to have something on top of them to protect the burners below and disperse heat. Originally, lava rock was used, but lava rock is not consistent in shape, size, or thickness. This means that lava rock is not real good at dispersing heat evenly in the grill. Lava rock also has holes in its surface, this allows grease to fall into the holes, which can not be cleaned out. This grease creates smoke the next time the grill is used affecting the taste of the food being cooked. Lava rock has been replaced by newer materials.

Ceramic and porcelain "rocks" are the replacement for the lava rock. Ceramic or porcelain rocks come in all shapes and sizes, some are round, some are square, some are shaped like a pyramid. Ceramic and porcelain rocks heat evenly and therefore disperse the heat evenly through out the grill. Ceramic and porcelain rocks are also non-porus. Grease that drips onto the rocks is burned off creating smoke that flavors the food, but is not present when the next food is cooked. The major difference between ceramic and porcelain, is that ceramic rocks will deteriorate faster than procelain. When the ceramic or porcelain rocks start to crumble, it is time to replace them.

Some grills use sheet metal or stainless steel racks that hold ceramic or porcelain rocks as grates. These types of grates are the most efficient at protecting the burners and dispersing the heat in the grill. Of course, the stainless steel grates will last longer than the sheet metal, and the better the grade of the stainless steel the longer it will last. In some grills, the rocks in the grates can be replaced as they wear out. In other grills, the entire rack has to be replaced and the grates can be expensive.

When you are shopping for a new grill, do not be afraid to take out the cooking rack and inspect the grates above the burners. Then take out the grates and look closely at the burners themselves. You have a right to know what you are buying. Also, check the warranty length and what parts of the grill are covered by the warranty. Most Chinese import grills are considered "throw away items", but if you buy a new grill every 3 to 4 years, you will end up spending as much as a good quality grill will cost, but the quality grill will last a life time.

In the next segment we will cover different types of ignition systems and cooking grates.

Gas Grill Components - Firebox

Tue, 06 Jul 2010 19:47:24 +0100

I my last segment, I discussed the things to look for in a quality grill and how to tell the difference between a quality grill and a poor quality Chinese import grill. I also touched upon where to purchase a new grill.

In this section, I would like to begin to discuss gas grill components, starting with the firebox. The firebox is the major part of the gas grill. It is the part, upon which, all ther parts attach. If the firebox is poor, it doesn't matter how good the rest of the grill is, when the firebox deteriorates and fails, you have to buy a new grill.

There are only 2 materials, IN MY OPINION, that are used in a quality grill firebox: aluminum and stainless steel. Aluminum fireboxes have been around since the 1960's when outdoor gas grills were first intorduced. The technology is tried and tested. Stainless steel grills have not been around as long.

So, which is better, aluminum or stainless steel........... drum roll please........ aluminum. Why you ask? Please, let me explain. Cast aluminum is virtually bullet proof. You don't have to worry about scratching the finish if you use the wrong cleaner on it. You don't have to worry about rubbing across the grain and scratching the finish. It will not rust, tarnish, or change color from the heat, I have serviced and repaired cast aluminum grills that were 20 years old, and becuase the firebox was intact, I could replace the ignition, the valves, the burners, and the grill was as good as new again. About the only thing that will happen to a cast aluminum firebox, is the paint will fade. Cast aluminum fireboxes also do something better than stainless steel ever will........ HOLD HEAT, and isn't heat what grilling is all about?

Now, is thrre a difference between aluminum fireboxes, you bet. Cast aluminum fireboxes are produced by pooring molten aluminum slowly into a mold and then slowly cooling it. The slow pooring and cooling process allows more of the gases to escape creating a thicker, denser, less porus, and stronger firebox. This process is slow, and you will only find it in higher quality cast aluminum grills.

Lower quality fireboxes are produced using a "die-cast" technique (think die-cast metal toys). In this process, molten aluminum is injected, under pressure, into the mold and cooled quickly, which doesn't allow the gases to escape as well. Die-cast fireboxes are thinner, you can tell because the firebox will be thicker at stress points, where things are attached, than the walls of the firebox. Advantages: faster production of parts, less material used, and more proft made. Disadvantages: thinner and more porus walls means a weaker firebox that does not HOLD HEAT as well as cast aluminum fireboxes. I have personally seen the sides of a Weber Summit die-cast aluminum built-in grill, melt from a grease fire. So, again, you get what you pay for even with cast aluminum.

OK, if cast aluminum is so much better. why are stainless steel grills so popular? They look nice. They are the "newest" thing, and they seem to say "upscale and sophisticated". Stainless steel grills do not work any better, some are actually worse, but, they sure do cost a lot more and require a lot more maintenance to keep them looking "upscale and sophisticated", like the neighbors.

Just like aluminum grills, there are differences in stainless steel grills as well. Nothing less than 304 stainless should be used in an outdoor grill. The main grill components, like the firebox, should also be made out of a thick guage of 304 stainless steel. In things like side shelves, the thickness is not as important, but it should still be 304. Anything less than 304 stainless steel will rust, corrode, discolor, and possibly warp. You are only going to find thick guage 304 stainless steel in high quality grills, so don't run off to Lowe's, Home Depot, Costco, or Sams Club to find a grill with 304 stainelss steel.

One other point, whether you are purchasing an aluminum or stainless steel grill, is the fastners that are used to hang things on the firebox. Fastners should be stainless steel. Believe me when I tell you that anything else will rust and corrode long before you call me for service or a repair. It takes a lot of time to cut the heads off of rusted and corroded screws and bolts, whcih means the labor cost goes up and so does the service or repair cost.

Now you have even more knowledge to help you make the best choice possible when purchasing your new grill. Next time, we will go over the different types of ignition systems you will find.

Outdoor Grills 101

Thu, 06 May 2010 17:08:54 +0100

Now that grilling season is upon us, it is time to take a look at different types of grills, grill quality, and how grills work so you will get the most enjoyment out of your new grill, or your existing grill.

Charcoal or Gas

The age old question: "Charcoal or Gas". This will be debated forever and there is no right or wrong answer. I will give just a few thoughts.

Charcoal advantages: better flavor (ok, but you can get the smokey flavor with a smoker box in a gas grill also), easy to transport, inexpensive, and traditional (most people my age can remember cook outs over charcoal when we were kids).

Charcoal disadvantages: harder to start (and then not all of the charcoal will light), hard to control cooking temperature, limited cooking time, and the worst part, cleaning up the ash afterwards. The "green movement" will probably have outdoor charcoal cooking banned all together (it is already being banned in some places).

Gas advantages: easy to start, easy to control cooking temperature, longer cooking time, easy clean-up. Rotisserie and side burners to expand cooking range.

Gas disadvantages: costs more (LP prices have gone up), not as portable (especially NG grills).

Gas Grill Quality

How do you know a quality grill when you see one? It is often hard to tell, even the inexpensive gas grills look nice on the outside, with lots of features and maybe some nice lights. I service all brands of outdoor grills (to the best of my ability) and in my OPINION, this is how the different grills stack up.

Chinese imports, the end cost (or cost you will pay to purchase the grill) is the fisrt concern for manufactures of Chinese imported grills. Once the end cost is determined, the manufacturer figures out ways to make the grill with good curb appeal and nice features, while cutting corners to keep the production costs down to meet the end cost and maximize profits (putting lipstick on the pig).

Since these grills sell for less the manufacturer, and dealer, must make money by selling a large volume of these grills to the uneducated public. The best way to move a large volume of these grills is through discount or warehouse type chains such as Lowe's, Home Depot, Walmart, Kmart, Target, Sam's Club, and Costco for example.

The Chinese import grills are inferior, not because of the way they look or their features, but because of the materials used in their construction. Plastic parts, painted sheet metal, thin low-grade stainless steel on the outside and low-grade interior components that do not perform well from the start and wear out quickly. Parts and service are often hard to obtain and a real hassle for the average person. I have done extensive research and I can take the hassle out of getting parts and servicing these grills, in most cases.

Some of the Chinese import brands to be wary of: Jenn-Air, Uniflame, Charbroil, Brinkman, Charmglow, Kirkland, and Member's Mark.

There are some manufactures of better quality grills that have either started to use Chinese parts in their grills or have their grills completely made in China: Weber (Dukane and less expensive grills are made in China), Vintage, Turbo, PGS, Alfresco and DCS.

Purchasing a Gas Grill

You can purchase a gas grill from many sources, here are the pros and cons, in my OPINION:

Internet Dealers:

Advantages: Large selection, easy to comparison shop, don't have to leave the house, low prices.

Disadvantages: Can't touch or see products, little if any personal contact with actual dealer, most internet dealers are "drop-shippers" who do not have a storefront, warehouse, or employee's. Most internet dealers will have little, if any, personal knowledge of the products they sell. "Drop-shippers" sell you the product and then have your product shipped to you from a distributor's warehouse or the manufacurer. Warranty parts and service are difficult to obtain, you will more than likely get refered to the manufacturer for warranty needs, out-of-warranty is even worse, the dealer, distributor, and manufacturer are probably not in your locality.

Discount and Warehouse Stores:

Advantages: Low prices, some selection, can speak to an employee (may or may not be helpful), can contact the store if you have a problem with the grill (may or may not be helpful), store is in your locality.

Disadvantages: Grills sold are most likely Chinese Imports, the store does not service the grill and may not have all replacement parts, you will have to deal with the manufacture for warranty and out-of-warranty issues.

Specialty Stores:

Advantages: Some selection, knowledgable staff, higher quality offerings.

Disadvantages: Some stores only sell one line of grills, some stores do not service the grills they sell, quality grills, highter overhead and lower sales volume result in higher prices.

Independent Dealers:

I had to create this category becuase I do not fit directly into any of the above. I am an authorized dealer of Modern Home Products outdoor grills. The Chef's Choice and Pro Fire lines. I have made the choice to only sell one line of grills due to the fact that MHP grills are American made, of the highest quality materials and componets, and offer a lifetime warranty on almost all of the grill, even the stainless steel burners. So, why buy from me?

Advantages: Low overhead (no storefront, warehouse, or employees) means low prices (even lower than the internet dealers), grills come directly from the manufacturer, I assemble them, deliver them, and install them, I service what I sell (as well as what everybody else sells), I will meet with you directly and help you select the grill that is best suited for your needs.

Disadvantages: I do not have dipslay grills that you can look at and touch.

As you can see, the advantages of buying a grill from me out weigh the disadvantages. I offer the best of both the internet dealer and the local specialty shop. I can not meet, or beat, the prices you get at the discount and warehouse chains, because the grills I offer are of much higher quality and built to last a life time.

Next Segment: Grill Components