Intermittent gas smell - Magic Chef gas oven

[Steve Fox]

Hello.

From time to time during the bake cycle there is a strong smell of gas coming from our Magic Chef gas oven. It seems to be coming from the rear vents of the oven, but on that point I could be mistaken.

I have recently replaced the bake ignitor, plus I have made sure that the burner tube is clean -- but still there is the gas smell. Again, this gas smell is not always present, rather we detect it only at various (random) times during the bake cycle.

The oven seems to heat up to the desired temperature without any gas smell, but then during the baking cycle we sometimes start to smell gas.

This gas smell only occurs when the oven is ON. The main gas line leading to the back of the oven was checked for leaks, and there were none. Also the oven itself was checked for leaks (pressure was applied to the gas inlet of the oven and there was no leakage detected in the oven itself.)

Our local repairman is scratching his head, thus I turn to you, my distinguished group of problem-solvers

Thank you in advance.

Steve Fox

[Dan O.]

Magic Chef gas oven

Supplying the model number would allow us to look up to see what design of appliance you're dealing with.

Forum Notice > Please include Make and Model # in post

during the baking cycle we sometimes start to smell gas.

Is the oven burner alight at that time?

Is the oven ignitor glowing at that time?

Those are the observations that will be necessary *at the time of the complaint* to try to determine the cause.

The burner should be alight whenever the ignitor is glowing (or within 30-60 seconds of it first being powered). The ignitor glowing but the burner not lit could allow unburned gas into the oven under some conditions... and only while in use (which is the only time the ignitor should be glowing).

You can read about how common gas oven ignition systems work and the observations and tests necessary to diagnose problems with them at the following link:

LINK > Understanding Gas Oven Ignition Systems

The main gas line leading to the back of the oven was checked for leaks, and there were none.

If a leak were there the smell should be constant not just when the oven was in use. That should be a big clue.

I have recently replaced the bake ignitor

In an attempt to correct this immediate problem or just sometime in the past?

Our local repairman is scratching his head

Did he measure the amperage draw on the ignitor circuit? What was it exactly?


Dan O.
www.Appliance411.com
The Appliance Information Site
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[Steve Fox]

Thanks Dan!

Dear Dan O.

Thank you very much for replying so quickly. I will do my best to answer your questions. First of all I am living in Israel so I am dealing with an 'export model' of a Magic Chef oven: m/n GM3468XUW-X. It was purchased in 1996.

In answer to your question if the oven burner is alight and is the oven ignitor glowing when we smell gas, I don't have an answer for you (at least not yet) -- since there is a bottom plate of the oven that prevents me from seeing the status of the burner and ignitor. I suppose I should run a visual test after having first removed the bottom plate.

Thanks for the link to Understanding Gas Oven Ignition Systems but I had previously read it, and it did not help me to diagnose my exact problem.

I replaced the oven ignitor about one week ago only as an attempted solution to this immediate problem. The repairman did NOT check the amperage draw, rather I checked it (but only when the new ignitor was totally disconnected from the oven's electrical system) - On the RX10 scale it read about 1.5 (one point five), but that number did not make sense based on www .appliance411.com/links/jump.cgi?ID=573 I can tell you that the "bad" ignitor I removed from the oven reads 1.9 (one point nine) on the RX10 scale when dis-connected from the oven.

I did NOT check the amperage when the ignitor was connected to the oven's electrical system. Would that be helpful, and if so, can you kindly describe how to do it?

Other than a bad ignitor or a clogged burner tube what other parts could be defective in order to cause an intermittent gas smell...any idea?

Thanks again, very much, for your time and effort on this one!

Steve

[Dan O.]

Amperage not resistance

since there is a bottom plate of the oven that prevents me from seeing the status of the burner and ignitor. I suppose I should run a visual test after having first removed the bottom plate.

Since your appliance is a range and not just an oven, operation of the oven burner may be visible from the drawer area beneath.

The repairman did NOT check the amperage draw, rather I checked it (but only when the new ignitor was totally disconnected from the oven's electrical system) - On the RX10 scale...

You can not check amperage while disconnected from power. Amperage is the amount of electrical current flowing though a circuit. Rx10 is used for a resistance test which is only useful if the ignitor was not glowing at all as explained at the Understanding Gas Oven Ignition Systems page.

I did NOT check the amperage when the ignitor was connected to the oven's electrical system. Would that be helpful, and if so, can you kindly describe how to do it?

It is the only meaningful test at this point. You'd need an ammeter or amprobe to measure it, tools not usually found in a homeowner's toolbox. It should have been preformed by the service technician.

I replaced the oven ignitor about one week ago only as an attempted solution to this immediate problem.

Than it might be safe to assume it is good. An amperage test would verify it with certainty though.

Other than a bad ignitor or a clogged burner tube what other parts could be defective in order to cause an intermittent gas smell...any idea?

Since you say the odor is only present while in use, the 'leak' would have to be in the gas system after the oven gas valve. Too little of gas being released by the valve to be ignited immediately is one possibility, or that released gas not properly getting to the ignitor to be lit. A defective gas valve or defective ignitor could cause the former. Plugged gas ports on the burner, the ignitor not getting hot enough or the ignitor not properly mounted are the only things I can think of for the latter.

JMO

Dan O.
www.Appliance411.com
The Appliance Information Site
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[Steve Fox]

Dan thanks again for the thought that you are putting into solving this oven issue. I will try to get someone to check the amperage, but I am rather curious as to when this amperage check is to made? Is the amperage test made after turning on the oven but just before the ignitor starts to glow?...or is it made while the ignitor is actually glowing red? or at some other point in the sequence?

Also, you say "the 'leak' would have to be in the gas system after the oven gas valve" but could another possible culprit be the "pressure regulator" which seems to be the very next part that is connected to the gas valve, i.e. let's say that the regulator does not allow the gas pressure to get high enough?

Thanks once again. - Steve

[Dan O.]

is [the amperage test] made while the ignitor is actually glowing red?

Bingo!

The amperage of the ignitor used on your model should range from 3.3 - 3.6 amps while in operation.

could another possible culprit be the "pressure regulator" which seems to be the very next part that is connected to the gas valve

The house gas line is connected directly to the regulator. Gas flows into the regulator and only then is distributed to the rest of the appliance's components. If the problem was the regulator, I would expect it to always to be leaking or if it just leaked under 'load' of use (I've never heard of such a case myself) whenever any gas component on the whole appliance was in operation (oven OR surface burner) which you say that is not the case.

JMO

Dan O.
www.Appliance411.com
The Appliance Information Site
=D~~~~~~

[HayZee518]

some regulators have a pressure vent right on the regulator, but the gas odorant smell would be right at the regulator not the appliance.

[Steve Fox]

Thanks both Dan O. and HayZee -

Dan, I will check the amperage of the ignitor, but being that it is new, it seems that the ignitor is likely not the culprit. So assuming that we can rule out a bad ignitor, and the fact that I have checked (and verified) that the gas ports on the oven (and broil) burners are NOT clogged or plugged, then I guess your analysis points to a defective gas valve -- I will try to get this checked out.

HayZee, I will also check for the presence of a 'pressure vent' on the regulator itself, and see if that seems to be the source of the gas smell.

Thanks again and good day to all ! Steve

[Dan O.]

I guess your analysis points to a defective gas valve -- I will try to get this checked out.

IF the oven valve is releasing gas but not enough to be immediately lit by the ignitor and the ignitor is definitely good and there is no problem with the gas ports of the burner nor ignitor mounting, yes, although rare it could be a problem with the oven gas valve.

BTW. There is no way to test the actual functioning of the oven gas valve in the field (besides if it was totally defective and not functioning at all). All that can be done is to insure proper amperage to it. If it isn't performing normally when that current is available, it can only be assumed to be defective as a result of logic.

JMO

Dan O.
www.Appliance411.com
The Appliance Information Site
=D~~~~~~

[Steve Fox]

New information for Dan O.

Hi Dan,

New information just in: First of all I tested the amperage of both the bake ignitor (bottom) and the broiler ignitor (top) -- both registered between 3 and 4 amps while in operation -- the scale of the amp-meter was not small enough to give me 'tenths' of an amp, rather the digital meter kept jumping between 3 and 4 amps.

Now here's the news: when I set the oven for 'broil' (which is a setting that my wife never uses, but I did this merely out of curiosity earlier today) the broil ignitor sure enough turned orange/red but... you guessed it, the broil burner did not produce a flame, and all I smelled was a strong odor of gas -- note the 'broil' setting was set to 'hi' during all of my broil testing. (I should note that during one of my tests the broiler burner did actually ignite, but only on one side of the burner, and the tips of the blue flame barely protruded from the broil burner, i.e. very very minimal 'flame').

Before I ask for suggestions about fixing the broil burner problem (yes, the inside of the broil burner is clean and the broil ignitor is in its proper place and seemingly has proper amperage), could you tell me if a faulty broil cycle could somehow be causing the intermittent gas smell we find when using the regular bake cycle? I am curious if the two cycles are related in any way?

Also, out of curiosity, do you know if the self-clean cycle uses the bake ignitor OR the broil ignitor OR both ignitors?

So before putting my oven back together today, I disconnected the electrical connection from the oven to the broil ignitor in the hope that that might somehow cure the intermittent gas smell we have when cooking using the bake cycle.

Thanks again for your help and I await, as always, your very useful feedback.

Steve

[Dan O.]

Accuracy

both [ignitors] registered between 3 and 4 amps while in operation... the broil ignitor seemingly has proper amperage

I wouldn't make that assumption with an inaccurate measurement. As stated above your ignitors should draw 3.3 - 3.6 amps while in operation (no more, no less). 3.2 is below that but still between the 3 and 4 amps you measured.

What type of ammeter did you use? If you used a clamp-on type, looping one of the power wires (assuming it is long enough) and measuring the current through the loop can increase sensitivity of the meter. A 2x loop should read 2x the amperage of a single wire. A 3x loop, 3 times the amperage, etc. Then you'd just divide the measurement by the number of loops measured.

could you tell me if a faulty broil cycle could somehow be causing the intermittent gas smell we find when using the regular bake cycle?

Some controls will power both bake and broil functions for an initial preheat cycle, others don't. If so, once up to temperature the broil would shut off and only the bake would be used to maintain temperature from there. I do not know how the control on your particular model is designed to operate. Someone could always look to see if the broil ignitor is being energized when bake is initiated.

do you know if the self-clean cycle uses the bake ignitor OR the broil ignitor OR both ignitors?

Often a self clean cycle will use both. I however do not know how the control on your particular model is designed to operate.

Dan O.
www.Appliance411.com
The Appliance Information Site
=D~~~~~~

[yachadm]

Low gas pressure

Steve,

Firstly, I'm not an appliance technician, just a technically-capable homeowner, who's tired of sloppy workmen charging outrageous prices.

I'm in Israel, and have installed my own appliances, and have the same range as you.

I had the same problem, but instead on looking for it inside my oven, I looked outside. I'm well familiar with the sloppy workmanship of the local tradesmen, and true to form, I found a kinked gas supply line, which dropped the pressure to a not-acceptable value, causing inability to ignite.

I replaced the gas line (myself - better workmanship than the locals), and since then, no problems.

Be aware that a low-quantity gas balloon will also create these symptoms.

I buy no appliance parts in Israel, absolute ripoffs, I order them from the US, and install them myself.

Menahem