Piezo spark lighter in both oven and cooktop

[Bill]

There have been at least three threads about adding a piezo lighter to the oven, and to the cooktop, and to both. This fourth thread will continue the adventure.

In the original thread, I added a spark lighter to the oven, and several members followed suit. It was a great mod, freeing me from the need to kneel down in front of the oven and stick a match into that dark inaccessible space under the broiler.
http://www.trailmanorowners.com/forum/showthread.php?t=3833

In the second thread, Harry Womack added a spark lighter to both the oven and the cooktop. It was an even better mod, but he had to buy new burners. Our member 13Dano found some stuff on eBay that made it a bit cheaper, but I have not found the same stuff since then.
http://www.trailmanorowners.com/forum/showthread.php?t=4928

Then tfcmarty performed a mod for both the oven and cooktop in
http://www.trailmanorowners.com/forum/showthread.php?t=5084
But he had to buy new burners, too, and there was some question about lighting four gas flames with a three-burner snapper.

So this is a fourth approach. My goal was to light the oven pilot and the main cooktop burner with one snapper, without having to buy replacement burners. Did I mention I'm cheap? We often use only the front burner of the cooktop, so this is a good solution. When we need a rear burner, a handy scrap of paper, lit on the front burner, will transfer the flame to the rear ones.

It turns out that one standard piezo lighter will produce a spark on two electrodes wired in series. That is, one side of the snapper goes to one electrode, the other side of the snapper goes to the other electrode. That is the way that the snapper manufacturer says they can be used in a propane barbeque. By way of background, you need to go to Home Depot, Lowe's, etc, and buy two replacement piezo lighter kits in the barbeque department, in order to get two "sideburner" electrodes - these are the units with the long electrodes.

Picture 1 shows the sideburner (long) electrode. You need one of these for the oven, and another one for the front burner of the stovetop.

Picture 2 shows the snapper as I originally wired it for oven-only operation in the first thread linked above. The red wire runs behind the stove and down into the oven. The black wire is a ground to complete the circuit.

In Picture 3, I have removed the screw that holds the stovetop front burner in place, and pulled the burner off (out of the picture). I have mounted the new electrode on a Z-shaped metal bracket near the spot where the burner will be reinstalled. I also dropped a short bit of glass tube over the electrode, to serve as an insulator.

In picture 4, the front burner has been reinstalled, but the electrode still sticks straight up in the air. The glass tube insulator over the electrode prevents it from sparking to the nearby burner body. The spark, of course, should occur off the tip of the electrode wire.

In picture 5, I have bent the electrode wire so that it produces a spark at one of the gas holes in the burner.

Picture 6 shows a couple things. First, the black ground wire that was originally connected to the snapper (in picture 2) has been disconnected and moved out of the way. It has been replaced by the red wire to the new electrode. Second, the new electrode has a lot of extra wire (red). I could have cut it out and removed it, but I simply coiled it up and taped it out of the way.

If you look carefully, Picture 7 shows that the new electrode protrudes up through the gap between the burner and the black stovetop cover. Again, the glass insulates it, preventing it from sparking to either the burner body or the cover.

It is not a wonderful solution - but it is another approach, and if you have already done the oven mod, it is a cheap and easy addition.

Bill

[lester2720]

Bill, Good job and a great ideal. The part I really like is, it does not require electricty to create a spark.

[B_and_D]

Great post, Bill. I would like to try this when we get all our other projects done.

I bought something similar to that when we made our son's potato canon, but the gun only has one ignitor. I think we had an extra one in the package, but probably threw it away. Oh well. It didn't cost much, you're right about that!

[larsdennert]

Hmm interesting. The snappers I bought seemed to indicate that one connector was for one ignitor and the second for the other ignitor. What lead you to believe that the outside connector is a ground?

The snappers in my BBQ are wired this way too. The snapper being a groundless static discharge device. Any thoughts? Maybe I could make my sparks stronger?

[Bill]

Lars -

Your signature has always said that you've done this mod, too. But I don't think you wrote it up - or did I miss it? We would welcome any tips or knowledge that would make it better or easier.

Anyway, when you go to Lowe's, Home Depot, etc, to buy the snapper and the electrodes, you'll find that they have two different kits on the shelf. One has a snapper, a short electrode, and a bunch of mounting hardware. The second has a snapper, a short electrode, a long electrode, and a bunch of mounting hardware. The first kit is labelled as being for a single-burner BBQ, and the instructions say to connect the electrode (red wire) to one connection on the snapper, and to ground the other connection on the snapper with the black wire. The second kit is labelled as being for a BBQ with two burners (a "main burner" and a "sideburner"), and the instructions say to connect one electrode (red wire) to each connection on the snapper, and discard the black wire. In this way, the pulse from the snapper runs out of the snapper, down the red wire to one electrode where it sparks to ground. It continues through the ground (the stove body) to the second electrode. There it rises and sparks to the second electrode, and runs back to the snapper through the second red wire, completing the circuit. In other words, the electrical pulse is split between the two gaps, and neither spark is as hot as it would be if there were only one gap. As a result, the gap adjustment is a bit fussier.

When I did the original oven-only mod, I bought the first kit mentioned above. The short electrode was kind of difficult to mount and adjust, though I managed it and it has worked fine. When I decided to add the stovetop to the mix, it was clear that I needed the long electrode, so I bought the second kit. So I ended up with two snappers, three electrodes - two short and one long - and a bunch of useless mounting hardware. If I were starting from scratch, I would buy two of the second type of kit, giving me two snappers, two long electrodes, and two short electrodes. Discard one sanpper and both short electrodes.

Incidentally, I think there is enough space on the front apron of the stovetop to mount a second snapper if you find you need a hotter spark.

Bill

[larsdennert]

Good info. Now I see how it works. I did do a write up on the link in my sig. Sometimes my burners light right off. Other times I click and click and nothing happens. I don't think the bugs are entirely worked out on my install.

[Bill]

Lars -

Yes, I finally see the writeup for your mod. It looks really good. It also looks like the electrodes you used are easier to mount than the ones I used, so that is something to be considered by anyone thinking about the mod. And I, too, noticed that the burner often lights more easily if you turn the knob to "low" instead of "high", so it doesn't blow the gas past the spark. I didn't expect that, but it makes sense.

So now we have another good source for how to do this upgrade. If anyone is considering doing it, I suggest checking out Lars' writeup as well as the others.

By the way, I was going to try out an electronic spark generator instead of a piezo generator. But I'm having trouble finding them as stand-alone parts. Am I missing something? If anyone has any ideas, I'd be grateful.

Bill

[larsdennert]

I agree on the gas level. I scored a mark for a new low gas level to light. From observing bbqs, it appears they have really worked out the position.

[lester2720]

Thanks for the information and I agree with Bill, the set up lars has would be a lil easier to mount. The only thing I'm missing is 4 electrodes and two snappers. Maybe I'm missing something can one of you (Bill/Lars)explain?
Thanks