JGBS21HEH4WW GE Range - Gas oven not holding temperature

[mc510]

Model Number

JGBS21HEH4WW

Brand

GE

Age

More than 10 years

Oven reaches selected temperature, but then drops a lot before re-igniting. It's especially noticeable when I'm cooking pizza at high temp 550; temp can drop as low as 400 before the flame comes on again. This is a fairly old oven without electronic controls, so the temp sensor and control boards discussed in other threads probably don't apply. Igniter, or thermostat, or ???

 

[Dan O.]

temp can drop as low as 400 before the flame comes on again.

What is the ignitor doing (glowing / not glowing) when the fame should be coming on again?

If the ignitor IS glowing but the flame isn't igniting, the ignitor is likely the problem. And yes, an ignitor can glow and still be defective.

These links are pertinent to your message. They were supplied by this message author. Please view them.

LINK > JGBS21HEH4WW Oven Ignitor (with repair video)

The ignitor needs to draw 3.2 to 3.6 amps to open the gas valve. As ignitors age, their resistance can go out of specification when they are hot which explains why it can function correctly when initially heating up but fail later in the heating cycle.

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

LINK > Understanding Gas Oven Ignition Systems


Dan O.

 

[mc510]

What is the ignitor doing (glowing / not glowing) when the fame should be coming on again?

Hmm, I'll try to check this ... I guess I should be able to pull out the broiler drawer and get a peek.

Based on your description, it seems possible that the ignitor isn't working properly at very high temps but then starts to work again when it's cooled down to 400. I guess I may or may not be able to confirm this just by looking at it. Even if I can't confirm, maybe it makes sense to replace it? Or is it possible that the thermostat or something else could cause these symptoms?

Apparently I replaced the ignitor in 2015. Pretty sure I got a genuine GE part. Failure after eight years?

 

[Dan O.]

I guess I should be able to pull out the broiler drawer and get a peek.

Possibly. Often the oven bottom panel can be removed to access the oven burner.

Even if I can't confirm, maybe it makes sense to replace it?

The ignitor does cause about 80% of ignition problems in such oven designs.

Or is it possible that the thermostat or something else could cause these symptoms?

A simple visual inspection could rule that out. If the ignitor IS glowing, the control system is not the cause.

Failure after eight years?

It is the most used component on the appliance and subjected to the highest temperature, not to mention the smoke and grease fumes during cooking. You should expect to replace it again in the future as well.

JMO

Dan O.

 

[mc510]

I posted recently about this problem (oven reaches set high temp, but then falls by as much as 150F) and was starting to think that the igniter was crapping out at high temperature. But I'm cooking pizza right now, oven is set at 550F, it's actually running at 400F, the burner has been on for at least the last ten minutes and the temp hasn't risen at all. I'm totally flummoxed. The burner doesn't have variable output, does it? It's just supposed to go on and off as necessary to maintain temperature? I just can't figure out why it won't maintain the set temp.

 

[Dan O.]

I posted recently about this problem

Please post followup as replies to your original message so everyone can follow the discussion from start to finish. Your messages have been joined together.

the burner has been on for at least the last ten minutes

Can you actually see the flame on the oven burner when the problem is occurring? You never replied with that information previously when I asked. It is important.

The burner doesn't have variable output, does it?

No. Some rare conditions could possibly reduce the size of the burner flame but that is extremely rare.

More common is all gas flow stopping (and thus all flame) at inappropriate and/or unscheduled times. The flame may fail in the middle of cooking and might even eventually start again afterward but not always when it should.

Direct observation of the burner and ignitor at time of failure is necessary. The key is, a burner flame should be present on the burner whenever the ignitor is glowing.

It's just supposed to go on and off as necessary to maintain temperature?

Yes.


Dan O.

 

[mc510]

I missed what happened when the temp fell from 550F to 400F, but then I directly observed the flame after that for ten or 15 minutes while the oven temp was not rising. I don't know, I guess this doesn't really make sense; maybe the temp had fallen so far that it was just taking a long time to come back up? I'm just going to go ahead and replace the igniter and see what that does.

 

[Dan O.]

maybe the temp had fallen so far that it was just taking a long time to come back up?

That can happen when the burner doesn't reignite quickly as it should. A clue to the cause is looking at what the ignitor is doing at that time. Otherwise all anyone can do is guess.

I'm just going to go ahead and replace the igniter and see what that does.

If you can't do the electrical tests or get the observations necessary to make an accurate assumption, that's all you can do. As I stated, the ignitor does cause about 80% of ignition problems in such oven designs.

LINK > JGBS21HEH4WW Oven Ignitor (with repair video)


Dan O.

---

Using the links provided in forum messages to trusted parts vendors helps support this forum and the professionals that give their time to assist you for free. Please give back.

 

[mc510]

Well crap; I replaced the igniter but when I went to make pizza this weekend, same problem. Set the oven to 550F, reaches 550F, then fell to 375F before climbing again.

I'm really wishing that I bought a new range a few years ago when I was looking at nice ones for under $700. Now it seems like you can't get anything at all for under $1200.

 

[Dan O.]

Set the oven to 550F, reaches 550F, then fell to 375F before climbing again.

What is the ignitor doing when the burner should be reigniting?

 

[mc510]

What is the ignitor doing when the burner should be reigniting?

I dunno, I'll take that as my next thing to figure out. Next pizza day in two weeks ...

 

[Dan O.]

Next pizza day in two weeks ...

Someone can always just turn it on empty and watch it but that's up to you.

 

[mc510]

Well, it's pizza day. Got the oven cranked to 550F; been on for over an hour and I've been watching the flame and temp regularly. Temp hasn't been over 500F for over half an hour, currently at 400F ... and I haven't seen the flame go out at all. Now, I'm making pizza, so I have to open the oven periodically, but only for five seconds at a time, and only every 8 to 10 minutes. Could that be enough to keep the oven from reaching temp?

 

[Dan O.]

I have to open the oven periodically, but only for five seconds at a time, and only every 8 to 10 minutes. Could that be enough to keep the oven from reaching temp?

No.

Temp hasn't been over 500F for over half an hour, currently at 400F ... and I haven't seen the flame go out at all.

I don't see how that's possible. The only way I can see that occurring is if the burner is only partially in flame. The temp should go way above 500 of the burner was staying on 100% of the time.

More direct observations will be necessary before we can suggest possibilities.


Dan O.