I have a six-burner Dacor gas (propane)cooktop that's about 12 years old. Recently one igniter keeps sparking after the flame is on. It will usually stop after ten seconds or so, but in the last two days it seems to go on forever. I've tried cleaning the igniter and burner per the instructions but it doesn't make any difference. Do any of you have any secrets that go beyond the manufacturer's recommendations? Thanks.

I am unfamiliar with propane cooktops, but I strongly suspect your problem is electrical. It seems that power is going to the igniter or "pilot" when it shouldn't. If so, repairing it will be easy, once you get to the wiring. That may be the bigger challenge.

In my limited experience with gas cooktops and ranges, the ignition takes place when the control is pressed in, and the gas is turned on when it is turned clockwise. So when the control is released the switch contacts controlling the ignition open upon release. What you describe sounds like the spring-loaded control knob is hangin-up on something. Try pulling out on the knob when the sparking continues after the flame is lit. Could be a little case of needing a touch of lubricant.??

We had a modern gas range with electronic ignition that didn't work right (though not what you describe). When the factory technician was servicing it (it was under warranty) I noticed that it had a surprising amount of electronics hidden beneath that smooth stainless steel exterior!

So it might well be an electrical / electronic problem that requires a new circuit board. (Something like a leaky capacitor or a blown transistor, etc. ?) Can you disassemble it a bit and look for a circuit board that could be changed out for a surplus replacement?

While I can not speak on your make and model, I can tell you that it would not surprise me that it has to do with flame sensing.

Some units like mine have a switch that when you turn the gas on towards the high end, starts the spark. When you back it off a little, the spark stops. Some, when you push the knob it, the spark starts. If these are the type you have, then it may be a stuck switch.

Propane, unlike natural gas, can accumulate in low pockets as it is heavier then air. For that fact I believe that when the gas is turned on, the spark continues until flame is sensed.

The way this is done is by “Flame Rectification”. A low a.c. currant is applied along with the spark power. As it passes through the flame, it is rectified to a d.c. currant. The ignition circuit sees this and shuts of the spark. If the flame goes out and the valve is still on, it starts sparking until it sees flame.

It is not uncommon for part of this ignition unit to go bad and for safety, fails so that the spark is on.

I think you need a new ignition unit for that burner. This is assuming that this is only happening on that one burner.

There is one other item that can happen. The metal spark rod that sticks in to the flame can get crystallized from the heat over time and not pass this low currant. It is the cheapest part so you may want to start there.

In checking the Dacor web site, they use this type of system and call it "Perma-Flame™." Should the flame go out, it will start sparking.

Do to the dangers involved with gas, I don’t think this would be a DIY job.

Hope this helps.