Sunbeam Electric Blankets Keep Failing

[Bruce]

Hi,

If there is a better newsgroup for this, please let me know.

In the past few years, I've bought two king size Sunbeam electric heating blankets. They were the mid- to high-end models. After less than a year the first one would no longer heat, and we sent it back for repairs. The repair (I believe they just replaced the controls) took six months turn around, and postage was at our expense. After a few months more, it went out again.

The second blanket, less than a year old, is having the same problem. After only a few months use, the blanket will not heat, although the control is set to high.

Has anyone else had similar problems with Sunbeam electric blankets? I really hesitate to send it back to the factory for repairs.

I've looked for other brands of electric blankets, but Sunbeam seems to be the only brand around. Are you aware of any other brands.

Sincerely, Bruce

[Ron Hardin]

A Doberman runs about 100.5 degrees and is very comfortable.

[Bruce]

Ron Hardin on 27 Nov 2003 had this to say news: [e-mail]:

I have 3 St. Bernards. It's called a three dog night. ;)

[wayne]

You may be sitting on them or have kids jumping on them and breaking the wires! I have always had better luck with an electric mattress pad more direct contact with the heat and they are made to be laid on so a bit more durable they also tend to be lower wattage so they use less power!

Wayne

[indago]

Only when it's in heat...

[Robert]

Same here. Had one repaired several times at my shipping expense of course. Purchased a new one, same issue after about one year. Unit draws about 35 watts max so the wires are connected, just very low heat. On the previous unit twice was the control unit, once was the blanket connector. No dogs, no kids, no rough use.

[Tony Hwang]

Was it made in China?

[flakey714]

Over the years I've had two Sunbeam E blankets. The first year they worked great, second year, no so great. By the third year they barely got warm @ all

[clare]

Ours is over 20 years old and still working fine.

[Micky]

How does that compare with the rating on it, or on a typical electric blanket** the same width as yours. If it uses 35 watts, the heat has to go somewhere, and it doesn't go back to the electric company.

**I looked at a couple ads for you but neither were rated in watts or amps or even volts.

I have 2 electric blankets, one that I bought 40 years ago when that landlord I wrote about wasn't giving enough heat, and another that's at least 30 years old. They both work but it's not a fair comparison because I rarely use either.

But when I do use it, I note that though the control goes from 1 to

10, I can't put it any higher than 1, or I can't take the heat. This would be in a room that is 67 degrees. I think if the room were 32, 6 would still be too hot. I'm sure it just turns on full power, and then off, but I haven't measure the watts used.

Are you careful not to fold it or put weight on the folds?. After all there are wires inside. Of course that would only matter if there are parellel paths and you broke one of them.

[Mark Lloyd]

[snip]

I've had 3 over about the last 10 years. I have had no problem with the heat dropping off, they would just not work after 3-4 years. It was the blanket that failed. I continued to use the first control, which I like better than the other two.

[Peter]

I'd had two problems with Sunbeam electric blanket controllers that I was able to fix myself. (1) The comfort zone corresponded to about number 1/2, and (2) the bedding would go from uncomfortably cold to uncomfortably hot before the thermostat would cycle.

To fix problem number 1, I removed the control dial by peeling off the decal in the middle, unscrewing the screw that holds the dial to the control stem and pulling the dial up. I repositioned the dial on the stem (only serrated inserts, no orientation key to prevent reinsertion at any amount of rotation) so that my comfort zone corresponds to #5 on the dial, pushed the dial back down and reinserted the screw.

To fix problem #2, I removed the bottom plate of the control unit by taking out the two small Phillips head screws. I turned an adjusting screw on the thermostat relay to narrow the gap between the relay arms, thereby reducing the temperature deviation required to cycle the thermostat. CAUTION: The adjustment screw will have 120V if the controller is plugged in. Either use an insulated screwdriver or unplug the controller before attempting this. You can tell when the gap is appropriate by turning the adjustment screw and then rotating the temperature control dial back and forth. You should aim for a position of the relay arms to cause the relay to open/close with less than a 1 number rotation of the temperature control dial. Before I did this, I was getting a 2-3 number deviation.

I've seen newer model controllers that may not yield to these fixes. My model is 10-15 years old and the controller is a rectangular solid with the temperature control dial at the very top of the box with a serrated knob on top to turn it, and a metal bottom plate underneath the controller.

[John G]

My Sunbeam blanket had a problem after a year or two. They repaired it and it has been working for several years.

[Micky]

I think I'm happy using 1, but people are always happy when they don't know better. I'll certainly look into issue 1, and the next one (2) too. Thanks.

[Micky]

You know, I thought there was a thermal-swtich in the blanket, that controlled the relay in the box, and the control was Yes or No. Not a thermal rheostat. ???

[Peter]

I may be mistaken, but my perception is that in my model of electric blanket, the thermal switches sewn in the blankets are over-heat (safety) protection sensors. I think the bedside controllers sense ambient temperature and have a built-in local mini-heater that warms up both the controller thermostat's bi-metallic sensor and the blanket when the relay is closed. When the local heater warms up the thermostat's sensor, the relay opens, turning off both the bi-metallic heater and the blanket. I use an electric blanket and have it sandwiched above a woolen blanket but below a bedspread with a comforter on top of the bedspread. The added insulation on top of the blanket maximizes retention of the blanket's heat. However, as our house cools off during the night (thermostat lowered from 68 to 58), I hear the blanket controller cycling more frequently and I sometimes have to turn down the blanket's controller to avoid feeling too warm.

[clare]

We just use the e-blanket as a pre-heater. Never sleep with it on.

[makolber]

OP...good question, yes I have 2 such blankets, one has stopped heating, th e other is still good.

I took one apart to attempt a repair. I was expecting to find a small sing le heating wire fed power at the two ends and maybe a break in the wire or a bad safety device.

But I was surprised to find instead a 2 conductor type of wire that was fed power across the two wires. Apparently the wire contains some special res istive material that connects across the two conductors and heats up all al ong the wire. In an analogy it is like parallel christmas lights instead of series. Also I think the material is self adjusting such that if a loc al piece of the wire gets too hot, the resistance goes up and the heat redu ces at that portion only. It worked well when it worked, the heat was even .

So i could find nothing wrong with the control or the wiring other than the heating wire had a higher resistance across the two conductor compared to the good blanket. So I can only conclude that whatever resistive materia l the wire is made out of, it deteriorated over time. There is no single p lace where the wire is broken, it is just deteriorated over the length.

So I thought i can fix this, simply get some of this special wire and repl ace it. Well i have not been able to find this wire on ebay or any other p lace that a consumer could buy say 20 feet.

If I get more information on this special parallel conductor heating wire, I'll post it here.

If anyone else knows anything about it, let us know.

The wire looks like ordinary two conductor with white insulation. It looks like ordinary two conductor wire, but it isn't it has some built in heatin g stuff distributed throughout it's length that connects across the 2 cond uctors.

Mark

[makolber]

the other is still good.

ngle heating wire fed power at the two ends and maybe a break in the wire o r a bad safety device.

ed power across the two wires. Apparently the wire contains some special r esistive material that connects across the two conductors and heats up all along the wire. In an analogy it is like parallel christmas lights inste ad of series. Also I think the material is self adjusting such that if a l ocal piece of the wire gets too hot, the resistance goes up and the heat re duces at that portion only. It worked well when it worked, the heat was ev en.

he heating wire had a higher resistance across the two conductor compared t o the good blanket. So I can only conclude that whatever resistive mater ial the wire is made out of, it deteriorated over time. There is no single place where the wire is broken, it is just deteriorated over the length.

place it. Well i have not been able to find this wire on ebay or any other place that a consumer could buy say 20 feet.

, I'll post it here.

ks like ordinary two conductor wire, but it isn't it has some built in heat ing stuff distributed throughout it's length that connects across the 2 co nductors.

looks like "self regulating heating cable" is a good search term

But that stuff is a bit expensive

Mark

[Ralph Mowery]

But I was surprised to find instead a 2 conductor type of wire that was fed power across the two wires. Apparently the wire contains some special resistive material that connects across the two conductors and heats up all along the wire. In an analogy it is like parallel christmas lights instead of series. Also I think the material is self adjusting such that if a local piece of the wire gets too hot, the resistance goes up and the heat reduces at that portion only. It worked well when it worked, the heat was even.

So i could find nothing wrong with the control or the wiring other than the heating wire had a higher resistance across the two conductor compared to the good blanket. So I can only conclude that whatever resistive material the wire is made out of, it deteriorated over time. There is no single place where the wire is broken, it is just deteriorated over the length.

So I thought i can fix this, simply get some of this special wire and replace it. Well i have not been able to find this wire on ebay or any other place that a consumer could buy say 20 feet.

If I get more information on this special parallel conductor heating wire, I'll post it here.

If anyone else knows anything about it, let us know.

The wire looks like ordinary two conductor with white insulation. It looks like ordinary two conductor wire, but it isn't it has some built in heating stuff distributed throughout it's length that connects across the 2 conductors.

Interisting. When I was a boy we had electirc blankets around 1960 and one went bad. It had some resistance wire in it like you would normally expect to find.

While I have seen and used some of the wire like you are talking about for pipes and also to heat other things I did not know they are making it in electric blankets now.