Can this blanket be washed? - Sunbeam Electric Blanket - queen

you do not wash electric blankets especially if you do not want to burnt alive by a shorting blanket or electrocuted by the blanket
that instruction is on the care of the blanket tag in big letters

The drain hose must be cleaned.

That's totally not true..unplug the cord from the blanket... Wash blanket.. Air dry..or dryer on low heat

There is a problem with the blanket. Since it started doing this just after washing (as per instructions), I suspect that somehow - running it thru the washer caused the problem.

Since it is an electrical device, if allowing to air dry thoroughly doesn't let it work as expected, you should stop powering it - and use it only as a non-powered blanket or discard and replace.

I'd suggest this link - "How to Clean Stuff":
http://www.howtocleanstuff.net/how-to-wash-an-electric-blanket/

I've linked you specifically to:
How to Wash an Electric Blanket

(There are different factors to consider based on your particular blanket, however you should find a solution here.)

wash the blanket then throw it in the bin
water and electrical components do not mix
electrical blankets are just a resistor element in ceramic covering and if you put that in a washing machine that is the end of the insulation

Wahing blankets in the washer depends on the washer and it depends on th blanket. If its a thin blank or small quilt than usually yes. If you have a comforter than I recommend taking to laundry mat. Top load washer is designed for between 18-28lbs of laundry. It may not feel that heavy but soak it with water than feel how heavy. If its a direct drive washer and you put too much weight in it the couple will break. If its belt driven you can break the belt or wear out the moter. If its a front load washer they are designed to hold more but The motor can only handle so much weight or it burns out. The belt could also break if its too much weight. The simplest way of determining it is if the blanket does not soak up alot of water ( thin blanket ) than its ok If blanket soaks up alot of water (comforter) take to laundry mat. I hope this helped. Anymore questions please comment me back.

it maybe there to many in the drum try one blanket at a time or 2 small blankets