Tuesday, June 21, 2011

4 burner Viking cook top troubleshooting?

Possible Causes of Continuous Sparking:

Defective spark wires.

Continuous high heat can cause spark wires to degrade. Use volt/ohm meter to determine continuity of spark wires. Look for obvious cuts/abrasions or pinch points. A defective wire can allow spark voltage to transfer through insulation to ground prior to reaching spark electrode. Under normal circumstances all igniters fire together and if the burner in question has found an easier ground path the spark will go there. It will not, however, in most cases have found a continuous ground path such as what the flame would provide under normal circumstances. This will cause the spark module to re-ignite.

Cracked Ceramic Spark Electrode

Itʼs important to determine whether the spark electrode is faulty. Physical impacts and high heat can cause the ceramic post to fracture or crack. If this occurs the spark can shoot through the ceramic insulation and will normally go to ground on the burner head rather than through the flame

Faulty Burner Grounding

From the spark electrode / burner to earth ground it is important that you have a strong connection. This can be interrupted in many different ways.

1. Soiled spark electrode
2. Soiled burner
3. Soiled burner head
4. Corrosion between the burner head and burner tube.
Normally this will appear as a brownish stain and can be easily cleaned with a small wire brush.

Any of these conditions can interrupt current flow. It is recommended frequent cleaning with a stiff plastic or soft wire bristle brush using pure alcohol or a window cleaning solution that contains alcohol. It is commonly thought that simple igniter cleaning is enough, it is not. You have to clean all three conductive components to ensure good continuity. A small amount of grease or oil can act as an insulator and prevent the spark from flowing properly.

It is common to find one or a series of burners that will only spark occasionally. As with the previously described scenarios check all possible ground faults. This is the number one cause of erratic sparking, not spark modules as is more commonly thought. If you have made certain thatyou have a strong flame current / flame placement / solid ground, replace spark module.

There are 2 types of spark systems...

One kind sparks all four burners at the same time and is controlled by the spark switch on the burner valve itself. On this type, once the burner is lit you move the dial to the cooking position yourself. If one of the switches on the burners gets wet or sticks closed, it will spark continuously. This type of module will spark all four burnes at once, regardless of which knob is turned.
On the higher-end units, the module is much more sophisticated, looking for each spark to find a pathway to ground rather than manually turning it off via the knob setting. On this type of module (which yours has) each burner sparks independently and only the burner selected will spark, and then only until the module has sensed a flame. For yours to be behaving irregularly after so short a time could mean that you have a poor grounding system on the stove. Be sure you do not have this stove connected to a GFCI circuit, or the module will not behave correctly.

I suggest replacing the spark module in case it is not a grounding issue.
There is ONE module and FOUR sepatate burner switches that feed it.

This is how each burner works for your viking 4 burner gas cook top :---
If you look closely at a finger of burner flame you will see that it is clearly made up of three separate elements:
1. Inner fuel rich cone
2. Ionized blue outer cone with current carrying capabilities
3. Outer air rich mantle.
When gas combined with air, burned energy is released in the form of heat and light. When the gas / air mixture is controlled, the outer blue cone will actually carry electrical current similar to a wire.
If we place a metal probe into this “Ionized Plume” and apply a voltage between it and the burner, current will flow. An important characteristic of a burner/flame/electrode assembly is its ability to mainly pass current in one direction. It behaves as a one way valve or rectifier.
Flame rectification systems make use of this directional characteristic when detecting a good flame to distinguish it from leakage currents that can arise due to moisture contamination, soiled igniter tip, poorly grounded burner spreader ring / burner head, cracked igniter insulation or poor house ground.
An AC voltage is applied to the electrode from the spark module and the resultant current flow which is greater in one direction than the other, is electronically detected. This current is very small, about one microamp.

The accurate placing of the electrode in the flame is important. This igniter tip needs to be perfectly located in the ionized outer blue cone to effectively send and then detect current flow. To break it down further, the spark module acts as a simple capacitor. It saves voltage like a sponge until it can hold no more. It will save and release this voltage approximately 3 times per second. When the voltage is released it follows the spark wire until reaches the spark electrode tip. The built up voltage wants to leave the tip and move to the point of least resistance. In a healthy situation this will be the burner. From the burner the voltage flow will pass through the burner head, burner tube, chassis and to ground. An interruption of this current path will cause the spark system to misbehave.

this is the exact wiring for the ignition module:---
The ingitor on this model is a re-inigtion type of module. It actually uses a path to ground thru the very flame itself to stop the burner from clicking. I believe that all 4 burners will show a spark even if you are only lighting one. Normal. The clicking means that one of the burner caps is not seated correctly to allow the spark electrode to go to ground as it should. Check that the burner caps are properly in place and not jammed on there in the wrong position.------------
The flame also plays a very important role in this process. Because the flame is conductive, it allows the voltage to pass through its body like a bridge to the burner. This bridge allows the built up spark voltage to bleed off of the igniter tip and move to ground more easily. The resultant ionized flame bridge has now become the path of least resistance for the spark to take across the gap between the spark electrode and the burner body.
By bleeding off the buildup of voltage we stop the spark from occurring. The spark is, in effect, still there, you just canʼt see it.
1. Continued reignition on top --1A. Defective spark switch or 1A. Replace switch.
burner. incorrect switch.
1B. Position of spark electrode 1B. Align spark electrode with burner
1C. Lack of or improper ground. 1C. Check ground outlet. Check ground at the module.
1D. Defective spark module. 1D. Replace spark module.

Each top burner valve has a switch mounted on it. Remove 1 wire from each switch till you find the defective switch. With all switches in off position find the switch with continuous continuity.--------------
In your case spark module is faulty and needs to be replaced.If above possibilities checked out ok.
This is how the spark module looks:---
Main Product View

To order the spark module click the link below:---