Hot Stove!

This morning I noticed that the cooktop cover on the 3 burner Magic Chef stove was warm (before use). Opened the cook surface pan to expose the burners and tubes. Found that the tube to the right rear burner was very hot to the touch. The burner was not lit and is about 10" from the manifold. The heat seemed greater at the section near the burner orfice at the first section off the manifold (section with the air-mixer opening). The knob for the burner was off. Stove had not been used for over 24 hours. I used a soapy water mixture on all connections without being able to detect a leak. After applying the soap water the tubing cooled. Could there have been a small flame at the manifold; not visible; for over 20 hours??? What else and why!!?


Thanks, Jerry

Is the pilot light in the oven on ?? If so, it could transfer heat internally up to the cooktop. Just a thought, God Bless ya, Al W

Sounds like the pilot light is turned up too high

Believe the pilot light was off. If it was on, would it have transferred heat to only the one burner tube? The burner tube was hot too the touch. The other two were cool.

I really need a handheld "sniffer". Just by coincidence I bought one three days ago... when I got it home it would not function properly right out of the box. Now that brings up another issue... Has any one used the Pocket Air Check gas leak detector? Any other recommendations for a reasonably priced handheld detector.

talley said:

This morning I noticed that the cooktop cover on the 3 burner Magic Chef stove was warm (before use). Opened the cook surface pan to expose the burners and tubes. Found that the tube to the right rear burner was very hot to the touch. The burner was not lit and is about 10" from the manifold. The heat seemed greater at the section near the burner orfice at the first section off the manifold (section with the air-mixer opening). The knob for the burner was off. Stove had not been used for over 24 hours. I used a soapy water mixture on all connections without being able to detect a leak. After applying the soap water the tubing cooled. Could there have been a small flame at the manifold; not visible; for over 20 hours??? What else and why!!?
Thanks, Jerry

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Jerry, Just before using the soapy mixture for detecting a leak, had you turned the knobs on and off? This sounds like one of those situations where a valve didn't completely seat and a very small flame was inside the burner or the tube. I don't think there is any way the oven pilot could have caused the stove top burner tubes to be hot. I would just keep and eye on it after use and before closing the lid. If it happens again it has to be the control knob for that burner.

Pilot lights on the burners?? I thought they were all electronic ignition. Yes the oven has on but I wouldn't think there would be that much heat from a pilot light.

talley said:

Believe the pilot light was off. If it was on, would it have transferred heat to only the one burner tube? The burner tube was hot too the touch. The other two were cool.

I really need a handheld "sniffer". Just by coincidence I bought one three days ago... when I got it home it would not function properly right out of the box. Now that brings up another issue... Has any one used the Pocket Air Check gas leak detector? Any other recommendations for a reasonably priced handheld detector.

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Ethyl mercaptan is added to propane for consumer use, just like it is to natural gas supplied to homes, etc. The human nose can detect one part of it in 2.8 billion parts air, so the sniffer on the front of your face should alert you if there is a leak well before the flammable range is reached.

As for the Pocket Air Check, it is calibrated to react at 2000 ppm propane (based on its reaction to 5000 ppm methane), which is well below the flammable range of the gas (2.15 - 9.60% in air). 2000 ppm equates to a 0.2% concentration in air (roughly 10% of the LEL, which is where "professional" detectors would read it as 100%), which should smell like a ton of rotten eggs. FWIW, most common gas detector devices are calibrated with methane and conversion charts are used to compute the actual levels for other hydrocarbon gases (if the user knows what it might be).

This info is from the manufacturer's website. It also says that the device is sensitive to shock, so if it's been dropped or whacked, it may not function. If your's does not work, I would return it. Be aware, also, that the sensors in gas monitors have a shelf life. Two years is usually the most we get from our 4-gas units in the FD before replacing sensors. And they cost considerably more than the Pocket Air Check.

FEATURES
• Detects Natural Gas, Methane, Propane, Hydrogen and Butane
• Locates leaks in pipes, valves, fittings and tanks
• Operates up to 8 hours on 2 – AA alkaline batteries
• Highly sensitive solid state sensor
• Eye-catching emergency yellow housing
• Only 6” long, fits easily into pocket or tool-belt
• Has both audible and visual alarm indicators
• Factory calibrated to 5000 ppm (0.5%) methane in air (equivalent to approx. 2000 ppm Propane)

So, unless you have a significant leak, the Pocket Air Check might not be able to pick it up unless you get the probe into the gas (which is heavier than air and will settle possibly lower than where you've got the probe pointed). And no, I've never seen or used one.

Corrrect... burners do not have pilot light, believe posts were probably referring to oven. But, I would discount the oven as playing a role. Ray, I tend to lean toward the knob not being completely turned off; allowing flame to travel back up the tube and maintaining a flame at the orfice. Absent some defect in the controls it may have been human error... never seen or heard of it before. Will be alert to a reoccurance and be better prepared to carefully assess the situation. DW and I may have touched the knob as a reflex and changed conditions.

John... Following my first retirement, I had used a handheld combustible gas detector in an environmental safety role at a college. It worked well for an initial screen in response to complaints of gas odors. Don't remember the name but was a red case with sensor on end of flexable wand. Cost was about $350-$400, don't want to spend that kind of money on this use. Just would like to have something instead of soapy water to probe and reach difficult connection locations. Your reference that sensors have life of 4 years... would that apply to the propane monitors we have in our Rvs?? It seems that I recall smoke detectors have a life of some 5 years.

talley said:

John... Following my first retirement, I had used a handheld combustible gas detector in an environmental safety role at a college. It worked well for an initial screen in response to complaints of gas odors. Don't remember the name but was a red case with sensor on end of flexable wand. Cost was about $350-$400, don't want to spend that kind of money on this use. Just would like to have something instead of soapy water to probe and reach difficult connection locations. Your reference that sensors have life of 4 years... would that apply to the propane monitors we have in our Rvs?? It seems that I recall smoke detectors have a life of some 5 years.

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Talley,
I don't know about the detectors in our rigs, might need to do some research on that, but the handheld units we use in the FD tend to have about a 2 year life on the sensors. I would not recommend that anyone spend hundreds on a gas detector, when their nose is probably more sensitive to minor leaks. Sensor life on smoke detectors and CO detectors in the home can vary. 5 to 7 years is common, some can go longer (or shorter). Depends on the method of detection. The hardwired smoke detectors in my home are 15 years old and still work. Occasionally, I'll hold a lit candle under them and blow it out, letting the smoke drift upwards. I make sure I have hearing protection on when I do that. Other times, the wife tests them by letting something spill over in the oven . That's why it pays to look in the booklet or on the unit itself for the signal that indicates a fault code and not a low battery or actual alert.

You can purchase relatively inexpensive detectors that double as smoke detectors and can detect gas. Read the labels carefully and pick one of the better ones. We have had good luck with them and they can even pick up when a non-vented heater is burning to high allowing gas vapors that haven't completely combusted. If you add an extra one purchase a good one.

My wife tests the smoke detector and the propane detector on a regular basis. Toast every day or so for the first; and hairspray just about every day on the latter.

Sounds like a great Safety drill. Whatever works.

lwmcguir said:

You can purchase relatively inexpensive detectors that double as smoke detectors and can detect gas. Read the labels carefully and pick one of the better ones. We have had good luck with them and they can even pick up when a non-vented heater is burning to high allowing gas vapors that haven't completely combusted. If you add an extra one purchase a good one.

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How about a link or brand name/model for one of those? All I can find are ones that either do smoke and heat rise, smoke and CO, or CO and natural gas. No smoke and gas ones.

But I thought the smoke and heat rise, and gases, CO2 and propane all sank because they are heavier than air.

Propane is heavier than Air we breath... CO2 is nearly the same weight as Air... which is why a ceiling mount detector works as well as one plugged into a 110 Volt outlet on the wall. CO2 moves freely as well... the blowing of a fan or the furnace blowing moves the gas through out the room.

Marv

2010augusta said:

But I thought the smoke and heat rise, and gases, CO2 and propane all sank because they are heavier than air.

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That is essentially correct, unless there is sufficient air movement to stir the gas cloud higher. Thinking of carbon monoxide as an example, if the furnace heat exchanger is faulty, the CO is being pushed through the ductwork by the fan, along with the warm air. With that, it can be dispersed at all levels of the occupancy. We had one call not too long ago where the blocked oven vents were the culprit in the kitchen, but the levels of CO in the bedrooms on the second floor were almost double the kitchen level. The running furnace in the basement (lowest levels in the house) was helping circulate it, even though it was not generating it.

That makes since, We run the ceiling fan all the time to move the hot air around.

JohnDar said:

That is essentially correct, unless there is sufficient air movement to stir the gas cloud higher. Thinking of carbon monoxide as an example, if the furnace heat exchanger is faulty, the CO is being pushed through the ductwork by the fan, along with the warm air. With that, it can be dispersed at all levels of the occupancy. We had one call not too long ago where the blocked oven vents were the culprit in the kitchen, but the levels of CO in the bedrooms on the second floor were almost double the kitchen level. The running furnace in the basement (lowest levels in the house) was helping circulate it, even though it was not generating it.

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Not to be argumentative or anything of the sort, but aren't most furnace cold air or return air intakes located on each floor or a structure and not in the basement? But what you say does make sense none the less because most cold air returns are located at or near the floor. CO does sink and there fore is picked up and moved arount by the furnace through out the house.

Just wondering. Keep up the good info and work...

rick_debbie_gallant said:

Not to be argumentative or anything of the sort, but aren't most furnace cold air or return air intakes located on each floor or a structure and not in the basement? But what you say does make sense none the less because most cold air returns are located at or near the floor. CO does sink and there fore is picked up and moved arount by the furnace through out the house.

Just wondering. Keep up the good info and work...

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Part of the problem is trying to convey the idea without writing a training manual for it . Point is, as you mentioned, that heavier than air gases will sink to a lower level unless something occurs to stir them up. Usually, that's air movement of some kind. There was an analogy of sorts on the TV the other night about a deep volcanic crater lake in Cameroon that had a small landslide along the bank. The slide stirred up the bottom of the lake, releasing the carbon dioxide that had been trapped down there under pressure. It rose up, spilled down the valley and killed some 2000 villagers around the lake.

I have the Kiddie PI9000, which is a dual sensor model: it has both types of sensors. Their are others out there that are good as well. If you mount them near the range they will go off if you have the burners on high so keep that in mind. If you add any detectors to the camper or stick house purchase the dual sensor type.