Plastic knobs melt when oven door opens...

check the knob form out to inside but usually just change new one coz usually the switch plastic housing are melting/burn that making the metal part in the switch contact..

You didn't say whether you have a gas or electric oven, or oven & stove. I'll assume you have a stove, just to cover all bases.

First, you should shut down the oven: a gas stove will have a valve on the gas line behind the stove. The valve will either have a red handle or a flat stem that usually has a hole in it. Turn either valve 1/4 turn to shut off gas, use a wrench on the flat stem. An electric stove should be shut off by flipping off the double circuit breaker for it in your electric panel. Do not unplug an electric stove when it is on; this can damage the plug &/or electrocute you.

Most likely the inside of the knob has stripped out. Look at the knob for a hole that has a setscrew in it: a small allen wrench or screwdriver will loosen the setscrew, most knobs don't have them and will pull off. Be careful to use even pressure on two sides of the knob; if you can't pull it off, use two butter knives or flat screw drivers to pry it up enough to get a grip on it.

Look at the center stem on the back of the knob, it will likely be cracked or stripped. Some stems have a D-shaped metal insert that strips out inside the plastic stem. If you have one, pull off a burner knob and compare the stems in the back, if they are the same size, put the burner knob on the shaft for the oven control, and use that knob to turn the oven control off.

If the burner knob won't fit, use your fingers or a pair of pliers (gently) to turn off the oven control shaft. If the shaft stops normally, you can turn the stove back on using either the gas valve or the circuit breaker. If you have a gas stove that doesn't have electric ignition (a clicking noise when you turn on a burner) you may need to re-light the pilots for the burners. Lift the covers off the burners to re-light the pilots.

If you have succeeded in turning off the oven, you need a new knob -- you can get one at an appliance parts store or maybe a hardware store. If the oven control did not turn off normally, I would leave the oven/stove turned off: the control itself will need to be replaced by a qualified repair person.

I have a $1.50 per knob solution: 1. Buy a 1/2 x 5/8 x 1 spacer at Lowe's ($1.50 each - get 5 pieces) 2. Clean knobs, remove back cover of knob and connect broken plastic parts with glue (liquid form). Make sure little metal inside the plastic is on front end. 3. Apply glue (gel form) around plastic then slide the metal spacer over. Add more gel glue to fill up space between plastic and metal. Might want to wait 30minutes then apply more glue if there is still space or gap. That's it! I recommend waiting 24 hours to let glue cure until putting it back on range. Now you can put cap back on but would need to make the whole a little wider using a grinder.I used a small flathead screwdriver and a hammer and just chip off small pieces until metal sleeve would fit. However, I think u can do without the cap if you have strong glue. I have pictures. Feel free to contact me for questions: [email protected] My wife is very happy, saved her a lot of money coz new ones cost as much as buying a new range itself! The knobs are very sturdy right now. Wide says it's actually sturider than when we first got the range.

I have the same problem. I have gone thru 2 sets of knobs for my LG Gas Stove. Even when I put JB Weld inside the knob to hold it together the knobs only last for 7-8 months of use. I am looking for a universal know with the same stem configuration to slip onto the shaft of the LG stove. It looks like a D

Very carefully''.

I had the same problem and searched extensively for a solution. They even have a video from GE on the net telling you how to avoid melting them, which is basically don't open to broil and make sure the seal is good on the oven. Essentially, don't use their oven normally like the rest of the ovens in the world. Finally I went to a few show rooms to look for a knob to substitute for the garbage ones from GE. On one of the new models they have a solid cast stainless knob (with a plastic shaft, I think it is delrin) which looks identical but has a longer shaft. I obtained the PN which is WB03T10262 and ordered one. I trimmed the shaft length to match the length of the defective knob with a hack saw, and had to trim out some mold flashing in the cavity. After a couple of fittings I was finshed and it looks fine. I then ordered 3 more from the Appliance Zone for $15.98 each. GE's price for the same part was $25.25!!

Same problem as well. Hoping to buy universal fit parts as GE wants $16/piece (x6) to replace the knobs. They WILL NOT cover under warranty.

HORRIBLE SUPPORT, POOR QUALITY PRODUCT!

NO METAL KNOB FOR THAT MODEL COZ IF USE METAL EVERY TIME U USE IS HOT THATS WHY DESIGN FOR PLASTIC,MUCH BETTER TO U REMOVE THE KNOBS AFTER U TUNN ON THE HOBS TO LESS MELT THEN RETURN IT IF U TUNR IT OR ADJUST.

I was able to find online some metal knobs that MIGHT work, but the prices ranged from $30 to 60 EACH, and I needed 5 - too costly for me!
The following 3 plastic knobs will work on your Jenn Air range, model JGR8875QDS. By "work" I mean they will fit your burner controls, operate the burners just like the factory knobs, and the markings on the knobs for "Off" "Lite" and "Hi" will be in the correct positions, similar to the factory knobs. (Exception: The last knob listed has markings somewhat different than the Jenn Air knobs.)

The following knobs do NOT look like your factory knobs - all three are made from black plastic rather than the (fake) silver metal look of the (plastic) OEM knobs. What I cannot tell you is if the following knobs will be more durable than the factory knobs - but then it's hard to imagine how they could be much worse.

-------- Burner control knobs known to work on the Jenn Air JGR8875QDS gas range --------

1. Whirlpool part number 74008850, made for some Amana gas ranges, will fit the Jenn Air. RepairClinic.com calls it part #1035119, and PartsSelect.com calls Item #PS2086316; it sells for $6-7 (USD). You can see a photo by entering the appropriate part number in the search box of either of the two websites mentioned above. The Amana knob is about a quarter-inch larger in diameter than the OEM knobs, but that does not cause any problems. Of the several knobs I tried this is the only one that tells me what it's made from - "PBT" - or polybutylene terephtalate, a thermoplastic which has a melting point of 430 degrees F and a maximum utilization temperature of 330 F.

2. Whirlpool part number 74009094, made for some Maytag gas ranges will also fit the Jenn Air. RepairClinic.com calls it #1035342, and PartsSelect.com calls it #PS2086544. It sells for about $9 on both sites. You can see it here: 
www.repairclinic.com/Appliance-Parts?s=t-74009094-%3d%3d
Like the Amana knob, the Maytag knob is about a quarter-inch larger than the OEM Jenn Air knob.

3. A third knob worth considering is available from AmericanStoveParts.com for $7 each. The front of the knob looks much like their OEM Replica Burner Knob 1104-B (but don't order #1104-B - it won't fit). The knob that will fit the Jenn Air is AmericanStoveParts #1214-025-B. You will have to order it by phone or email because it is not shown on their website. (As of October 2009, none of the knobs shown on AmericanStoveParts.com will fit the Jenn Air.) 

Notice the markings on the 1214-025-B are not quite like the Jenn Air markings, with the "HI" and the "LITE" positions being reversed. Also, the 1214-025-B knob I received did not have the white dot at the "OFF" position nor the white ring around the periphery as shown in the photo of the 1104B knob. The total diameter of the the 1214-025-B is 2" - the same as the factory Jenn Air knobs.

While I don't think the front of 1214-025-B looks quite as nice as the Amana or Maytag knobs, the back of the knob appears to be much more robust than on the others. The extra plastic MAY make this one more durable. 
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I have installed the Amana knobs (#1), and I will report back if it proves unsatisfactory.

www.sears.com go to the parts dept and have make and model ready....this will fix ya!