12 replies to this topic

[isen]

I have recently bought a house and with it I inherited a Kenmore gas range/oven. I don't know its age, but its model number is 119.7498893. I can no longer order a manual for it on the Sears/Kenmore site. It was working until two days ago when I discovered that it will not heat; the stove burners still work.

From reading this and other forums I realise that there are a few types of ovens (glow plug, constant flame, and spark. . .is that right?), but I don't know where to look in the oven to figure out what kind I have (i.e., where exactly should the glow plug, pilot light, etc., be so I can look at it). . .and, knowing that, how do I go about remedying my situation? if it's a repair I can do, what do I do, and if it is not who do I call?

I am mechanically inclined, but I have never worked with an oven or gas before.

thanks,
Tom Isenbarger

[Samurai Appliance Repair Man]

It's hot surface ignition. The ignitor is item 23 below:



The only reliable way to test the ignitor is to measure its current draw. but most people don't have an amp meter. In this case, see if you're getting 120v to the ignitor when you turn on the oven. If so, then approximately 87.93% of the time, the problem is a bad ignitor.

[isen]

Thanks, Sam (can I call you Sam for short?), for the quick response.

I do have a Fluke 177 True RMS multimeter that I used to use to take resistance readings from thermistors. I could make a voltage reading for sure with that, and probably a current reading too. What should the current be through the ignitor?

[Samurai Appliance Repair Man]

For yours, the flat Norton ignitor, 3.2 to 3.6 amps:

[isen]

So I finally investigated my problematic Kenmore oven. I removed the screws that hold the glow element so I could get to the wires. When I tested the wires with my multimeter, I only saw a voltage (~120 V) when the oven control knob was in a certain position. This may be the BROIL position, and if it is not then it is very close to BROIL (much of the type is worn off the dial). The dial clicks in to this position from both directions.

After reattaching the old glow element, I noticed that it does in fact glow when the dial is in this position. (Is there a LIGHT position on these ovens? Again, I cannot make out what the text on the dial reads, so I don't know*). So, if I leave the dial in this position, the glow element glows and after a bit the flame along the top of the oven ignites. If I then move the dial to another position clockwise (the oven temperatures), the flame eventually goes out.

Is this a problem with the thermally-activated valve that controls the gas flow?

I am curious, in normal operation, does the glow element always stay on during cooking or does it only come on to light the flame initially and then go out?

*Also, we don't have a manual for this oven and I cannot get one from Kenmore as they don't supply them anymore. Do you know where I can get a copy?

[Pegi]

When the bake or broil settings are selected in your range, the ignitor starts glowing for which ever you have selected, bake or broil. .  When the glow bar gets hot enough to pull the amps and voltage down to the rating of the gas valve, the valve will open, and the ignitor will light the gas coming from the burner.  The ignitor stays on anytime the oven is calling for heat and holds the gas valve open.  When the selected temperature is reached, the thermostat cuts power to the ignitor, it cools down and the gas valve closes.  Now, is the ignitor coming on and glowing to the bake burner???  Or is it staying dead.  If it is dead, check to see if it is broken and replace it if it is.  If the ignitor comes on but the burner does not light, it is a 99%  chance the ignitor has gotten weak and does not get hot enough to open the gas valve. If you have cont. across the terminals on the gas valve, chances are it is ok.  But if the ignitor does come on and no ignition I have always found replacing the ignitor fixes the problem.  It does take 2-3 minutes for the glow bar to come on and get hot enough to open the gas valve, so do not expect it to light right at first.  Keep us posted with the results of your testing please.  Remember the gas valve is only 2.6-3.6 amps./volts. Do NOT hit it with 120 volts.

[isen]

So, are there 2 burners? One on top (that I can easily see) for BROIL and one on the bottom for BAKE? Are there also 2 glow plugs, one for each burner?

If so, do I have to remove the bottom of the oven chamber to see the baking burner and glow plug?

I have left the oven on now to see if it is heating.

[Samurai Appliance Repair Man]

[user=288]isen[/user] wrote:

So, are there 2 burners?

Yes.



 

One on top (that I can easily see) for BROIL and one on the bottom for BAKE?

Yes.


 

Are there also 2 glow plugs, one for each burner?

Yes.



 

If so, do I have to remove the bottom of the oven chamber to see the baking burner and glow plug?

Yes.

[Samurai Appliance Repair Man]

I've seen cases where an ignitor that is marginal doesn't fully activate the bimetal in the gas valve causing it to eek out gas rather than opening fully.  Could also be a bad valve.  Since it is ambiguous, on a job where I have a known bad ignitor and I smell gas, too, I always replace the gas valve along with the ignitor just to be safe.

[Pegi]

If your broiler is at the bottom of the oven, and there is not a second burner at the top of the oven, the same burner, ignitor and gas valve control both functions. If you have a second burner at the top of the oven for broil, you will have 2 burners, 2 ignitors and usually one dual gas valve that feeds both, seperately of course.  IIf you have the two burner set up, and your broil works but not the bake, the first thing to look at would be the ignitor to the bake burner on the bottom of the range.  It can be dead (broken) or it can come on but not get hot enough to open the gas valve.  A weak ignitor can cause the oven not to light, or light sometimes or light with gas escaping into the oven cavity since it would not be opening and closing the valve fast enough.  Of course you could have a bad thermostat, but take a look-see at the ignitor  first.  Pegi