I have a gas oven and I’m having (what I assume is) a strange problem. You set the temp, the gas fires up and begins heating. About 50 -75 degrees (verified with an oven thermometer) before it get’s to the preset temp it beeps and the preheated light comes on. Now if that was the only problem it’d be easy to deal with/calibrate. What’s strange is that after it beeps it continues to heat until it reaches the temp it’s set to. So why would that happen, and is there away to fix it? My guess is that there’s a circuit board that needs to be replaced OR the are two thermometers inside and one of them isn’t working.
sounds like a thermostat problem, those are pretty easy to switch out, call your local applaince parts store.
That was my first guess, but it’s strange that it beeps and says it’s preheated long before it actually is, but it still continues to heat to the preset temp. I’ll look into it, I’m pretty handy at taking things apart, so it shouldn’t be too difficult.
Actually, it sounds like a case of good design.
The oven “dings” and shuts off the current to the heating coil when it thinks the temperature is going to hit the desired one. At that point, you have a few hundred grams of metal heating coil glowing at a moderately bright orange (up to 850-950 K = 575-675 C = 1050-1250 F) and a few hundred grams of dark-enameled IR-absorbent metal at temperatures ranging from 1000F to 800F.
The metal walls heat up much faster than the air, because the coils heat the air primarily by raditaion and absorption. Dark surfaces absorb IR very effectively, while air is relatively transparent. That’s why you can feel the heat from a heater (or “cold” from a window in winter – which is actually lost body heat that isn’t being replaced by reflection or re-radiation as occurs with the surrounding walls) quite readily even if you are 10-20 feet away from it. If air absorbed IR effectively, then the temperature gradient in air would be much higher, and a pleasant warmth at 10-20 feet would be unbearably scorching at 1/2-1/4 the distance.
Without going into the difference in specific heat between air (higher) and metal (lower), we can note that there are only a few hundred grams of air in an oven (about 30 g/22.4L or 38g per cu. ft) so the several hundred grams of hotter metal will continue to substantially heat the air in the oven after the electrical or electronic thermostat cuts power to the heating coil.
If the circuit waited until the oven air temperature hit the target temperature, then it would substantially overshoot the target, and might scorch your food. You can test this hypothesis by changing the heating pattern in the oven and graphing the temperature curve. (I love inexpensive digital kitchen thermometers!!
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put the shelf onthe lowest level and cover 80% of it (no more than that - it could be a modest fire hazard) with aluminum foil to keep the radiant heat from hitting the upper oven where the temperature sensor is typically located
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put a large rectangular ennameled steel broliing tray or cast iron griddle plate or several cast iron pans on the shelf to absorb and re-emit the radiant IR. rather than reflecting it, as the aluminum foil does.
It’s similar to driving a car: you hit the brakes before you reach the stop light. When towing a heavy trailer, you hit the brakes sooner
eh, um, he’s got a gas oven…I don’t think there’s a metal coil.
Yea, gas oven. Anyways, I thought about that idea though. At first I was thinking it beeped earlier (and then continued heating) because after opening the oven/putting cold stuff in etc… it would have to turn the gas back on and reheat due to heat lost. But that still doesn’t seem right. Besides you’ll cause problems cooking when something needs to be cooked at 400 degrees for 30 minutes, but you end up cooking if for 10 mins at 350 and 20 at 400. I’m still wondering if it’s either got two thermometers (should be easy enough to check) or a circuit board is fried.
Stop in at the Johnstone Distributor by Timmerman Field and talk to the guy at the desk. He’s Arab and his English is a little broken, but he’s extremely knowledgeable about things like this. You can also call the manufacturer and get a copy of the wiring diagram, and or visit the website. The wiring diagram may also be on the back side of the oven itself (they have been on mine in the past).
If all else fails, call a service tech at the factory or E-mail them and they should be able to tell you if the oven is designed to work the way you are reporting.
KP, I see your point, but the heat coils or the actual flame itself could still shut off in anticipation of the oven heating up to the correct temp without the Pre-heat light coming on untill it ACTUALLY reached the correct temp.
Flame goes out, oven continues to warm up, then Pre-heat light comes on. That’s how it should be.
I’d recommend www.repairclinic.com . They have an extensive troubleshooting guide, and of course they sell the parts you need to fix what’s wrong. They saved me $$ when I fixed my gas oven and my electric dryer.
Disclaimer: I neither work for nor invest in repairclinic.com. I don’t have a dog in this fight.
Has it always been this way or did it just start happening recently? If it has always behaved this way, it might be by design, perhaps with the idea that it’s warm enough to put the food in, even though it’s not fully up to the desired temperature yet. Or maybe under the assumption that you aren’t just standing there waiting for the light to come on, but that by the time you notice the light is on, it will be fully heated.
Slightly OT, but are gas ovens different than electric? I’ve never had a gas oven, but all the electric ones I’ve ever used have the light on while heating up, and goes off when the desired temperature is reached. I know the oven is preheated when the light goes out, not when it comes on.