Air Date: November 7, 2007
A water heater can explode and shoot through the roof of a house like a rocket.
confirmed
In small scale testing, the Mythbusters started with a small six gallon water heater and disabled all of its safety features under the theory of poor installation or neglect. While the water heater eventually ruptured, it did not explode like a rocket. The Mythbusters then upgraded to larger thirty gallon water heater which exploded with significantly greater force, sending the water heater several hundred feet into the air. In order to confirm the stated myth, the Mythbusters obtained a full size fifty two gallon water heater and built a shack around it with a roof that followed standard California building codes. The water heater eventually exploded, shooting through the roof five hundred feet into the air and disintegrating the shack. In light of these results, and the fact that there is documented evidence corroborating the myth, the Mythbusters deemed it confirmed.
If a person is being dragged by a horse, the friction caused by the movement will make their jeans catch on fire.
busted
Wearing full body padding and a denim shirt and jeans, Tory allowed himself to be pulled along the ground by a horse. While the movement and friction did increase the surface temperature of the jeans, it wasn’t enough to cause the jeans to combust. The Build Team then moved the experiment into the lab, where they simulated the friction caused by being dragged by a horse with a power sander. However, when they applied the jeans to the power sander, the jeans were torn apart before they could combust. The Build Team agreed that friction alone cannot make jeans catch on fire.
Shrinking jeans while wearing them in a hot bath for six hours can kill you.
busted
The theory behind this myth is that if a person wore a pair of jeans and sat in a hot bath intending to shrink them to fit, the shrinking jeans can cut off blood circulation to the legs which can cause a lethal clot or require the legs to be amputated. The Build Team experimented with a pair ballistic gel legs with tubes running through it to simulate blood vessels. They then covered the legs in jeans and put it in a hot bath for six hours, but found no change in blood flow. They then had Grant wear a pair of blue jeans and had him sit in a hot bath for six hours. During the experiment, Grant was continually monitored by a medical expert and by the end of the six hours, he was declared healthy and in no risk of death. The Build Team decided that the myth was busted, but reminded the audience that blood clots and cutting off blood circulation are very real dangers and should not be taken lightly.
Newer: Episode 90: "Supersized Myths"
Older: Episode 88: "Trail Blazers"
[...] And now, Frank and Sarah have had an exploding hot water heater at their home here in Florida (confirmed by the Mythbusters). The one they’re trying to [...]
February 21, 2008 at 10:17 AM
Like the 747 v taxi, the water heater wasn’t much of a myth. This is clearly plausible from the onset and so the episode was just a demonstration. It was the coolest thing I’ve ever seen on TV though! Since there is NO WAY I’d try this at home, I really enjoy the show.
November 29, 2007 at 9:11 PM-Dan
I have also heard of an exploding water heater. I really like the way you scientifically approach all of the myths. The problem I have with your water heater test is that the tank was made into a sealed vessel by plugging the water inlet line and T&P valve. In a real house with all safety devices disabled the pressure in the tank would surely increase but not higher than the incoming line pressure from the street main, rarely higher than 125 psi. The presure would push back into the street main. I do really enjoy the show.
December 16, 2007 at 1:24 PMMike
About the shrinking jeans myth, it was a girl who bout jeans that was skintight to begin with, and then went swimming in them, and let the sun dry them on her.
December 17, 2007 at 11:30 AMFor the hot water heater myth:
The myth was whether or not the hot water heater would launch like a rocket or explode like a bomb.
December 18, 2007 at 4:03 PMHey, last year, for the Science fair I dicovered that if you shake hairspray up ( in a arisol can) then spary some in a cap without a hole the cap will explode because of the reaction of the carbon dioxide in the unstable inviorment. (that was my concution in the fair, I would have won, exept I had umonia and couldn’t show up in time so I was diqualafied) This from a 10-year old!
December 20, 2007 at 11:11 PMI do Oklahoma’s longest-running morning radio show (26+ years!)…but on Jan. 20th, 1982, I was going to report on some small story, when I heard the Star Elementary School in Spencer, OK., had exploded. The hot water heater beside the school’s cafeteria had a jammed relief valve, and the explosion killed 6 students, and one teacher. We had media from all over the country come to cover the tragedy, even landing helicopters in the parking lot of a funeral home next door to the school. I even personally had to put out a grass fire across the street, started by a non-moving line of cars that had gathered to witness the
December 31, 2007 at 9:16 PMcarnage, and their catalytic converter
under the car caught the grass on fire! I’ll always remember that day, as will most Oklahomans…and it’s proof a water heater CAN be deadly.
Dan Stroud, KXY Radio
OOOOOOOOOOOOOOWWWWWWWWWWWWWWWW!!!! I FEAL SORRY FOR THE PEOPLE THAT THIS HAPEND TO.
January 1, 2008 at 2:09 AMI am a vivid fan of Myth Busters. I am fully aware of hydro dynamics However there is one built in safety system on a hot water heater. The incomming water connection. If all of the other safey devices were disabled the increased pressure would simply over come the incomming water supply pressure. This would occure at 100 PSI or less and the hot water heater would stay well within it’s rated pressure. Results no explosion. This of course if the water service has not been shut off. So there you have it 3 safety devices.
Thanks, keep the episoids comming
January 1, 2008 at 5:14 PMMike
The hot water heater explosion referenced in the show occurred in Burien, Washington located 10 miles south of Seattle. For a link to the story go to http://www.komotv.com/news/archive/4014621.html The water tank went through a large beam and 2×6″ car decking (flat roofed building) before coming to rest some 460 feet away. The rear of the store was cinder block and was blown out by the blast. The small strip mall was later torn down due to the damage. A plumber had capped the relief valve believing it was defective. He had intended on returning the next day to replace it.
Another water tank explosion occurred in Kent, Washington in the early 80’s. The hot water tank was located in the basement of a church. It caused significant damage when it rocketed through the roof of the two-story building coming to rest in an adjacent lot.
Love the show!
January 1, 2008 at 11:17 PMI want to point out a couple of things that you need to consider.It is the fact that most municipalities in urban areas now have backflow preventers at the meter or where the water line enters the building, this creates a “closed system” this arrangement WILL allow pressure to build to extermely high levels, Thermal Expansion tanks and relief valves limit the pressure to less than the rating of the T+P valve. You must also consider the incoming static pressure starting at 55 or 60 psi, this baseline pressure would help the problem happen faster, It all must work together to be safe
January 2, 2008 at 5:00 PMQuestions welcomed
I personaly love your show.You should try a florida myth.try if you have a fanboat in the back of a pickup truck the fanboat can push the truck.Oh by the way I am 10.
Glocester,RI
Please write back Adam.
January 9, 2008 at 7:07 PMJeans can kill you? I’ve swam around in a pool for about 8 hours with my clothing on to test this at home (Aswell as it being a Saturday night party =P) and erm.. Well. If you tire out too quickly.. But that’s in a pool or the ocean. If you manage to tire out in a bathtub, you have some *deep* issues to sort out.
January 15, 2008 at 2:48 AMIn reply to Mike about the pressure not exceeding city pressure, that is mistaken. A pressure reducing valve, check valve or most newer water meters would restrict backflow into the city water supply, which is why most locations require a seperate expansion tank be installed now to give the pressure somewhere to go or it can build and leak at the T&P valve even under normal conditions.
January 15, 2008 at 11:44 PMJeans Can Kill You
The one parameter you didn’t appear to control was the water temperature.
You simply left your man in the tub for six
hours letting his skin go wrinkly.
Water temperature is very subjective, the
lady wife does washing up in water that
scalds me.( I mow the lawn)
Put a sample of denim in water at a controlled temperature, then check the ammount it has shrunk, you could also put
a force meter on another sample and check
the force it can exert whilst trying to shrink, then do your tests again.
Friction
Replace the sandpaper on the belt sander
March 10, 2008 at 4:53 PMwith a lenght of denim.
Increase the speed of the sander by a factor of five or ten.
If gas will burn it, so will friction
Hi- Love the show. I would like to see Tori and Grant do more controls (or at least talk about them on the show) for their experiments. For example- with the pig blood/denim jean shrinkage experiment: there should have been a negative control and positive control (tubing running through tub without any possibility for constriction-proves pig blood is not coagulating), and a positive control- another tube that they artificially constrict to show that the pump and blood flow can be constricted (perhaps the pump was compensating for any constriction).
As scientists, we know that proper controls are fundamental to doing good research. Plus you guys are responsible for teaching viewers about how scientists think! :)
Cheers-
March 20, 2008 at 12:56 AMRobert
How long did it take for the water heaters to hit the ground after exploding? The 30 gallon went “several hundred” feet and the 52 gallon went “five hundred” feet.
March 23, 2008 at 2:43 AMWater Angel.An early warning detection system on your geyser to protect the geyser from exploding.Also a electricity saving device.www.waterangel.co.za
April 9, 2008 at 1:25 AMFor the jeans catching on fire, I agree the sanding belt should not be sand paper but something with a high coeficiant of friction but low abrasiveness. it might even catch on fire at the speed they were useing, but if not certianly a higher speed would catch them on fire.
May 8, 2008 at 9:57 PMThe hot water tank… AWSOME!! I am watching a rerun of it right now!!
Id like to know whether a water heater would explode and burn down a house due to “flammable” fumes in the same room - a storage room.
June 28, 2008 at 8:01 PM