Calories burned reported on HRM seem WRONG

I just bought a Polar F6 and am so frustrated.  I did a turbo jam work out for 40 minutes and it reported that I burned a whopping 34 calories - I have a hard time believing that since I was sweating and panting.  Last night I ran 4 miles and it said I only burned 256 calories.  Any website I read where I enter my weight, time, distance always shows great calorie burnage....any advice?  I have set all the settings accuratley on the watch - maybe I need a different brand?!?!

HELP!

Alot of times on the F6(at least for me), you need to be careful about the strap you attach on your back. At times the strap won't really record your heart, you need to make sure the sensors on the strap are pretty moist, and that the strap is pretty snugly fit on your back so it doesn't slide around. I still struggle with having it properly monitor my heart rate at times, sometimes it just doesn't want to grab my heart rate, and it records me sprinting(for example) and only recording me as having 70 bpm when it should be around 160-170. That will throw off the calories burned by alot.

To make sure that your HRM is recording from the strap correctly, make sure you look at your watch alot to make sure the watch is constantly updating and changing your heart rate.

You won't find a better brand of heart rate monitor than Polar and the F6 is an excellent model but like any tool you need to learn how to use it.  Give it some time. Make sure you are doing everything right and have it set up properly.

I have had a Polar F6 for about 3 years and ironically just sent it back for service (battery replacement and a new transmitter) because it wasn't accurately keeping my heartrate.  I realize 3 years is a long time and I wear it for some type of activity about 4 days a week, so I had no problem with the $50 invoice for its repair.  Before this, I never had a problem with it - if anything, it usually registers higher calorie burn that what the gym machines compute. 

As said above, make sure the sensors are wet, and tight around your chest (right under my boobs), perhaps go thru your setup again (maybe your weight or something was entered incorrectly) and give it a little time.  Polar's website isn't the best for support regarding technical issues, but you could try that avenue.  I'd say if it isn't working better in another week or two, and after trying the above, see if you can return it to the store for a replacement.  With the experience I've had with mine, I would highly recommend it, so maybe you just got a lemon.

arg I have been having the same issues. I just bought mine about a month and a half ago. It seems to happen at the beginning of my workouts, but all of a sudden it will jump from 170 to 45 or 00! It is so frustrating because I make sure I wet the strap, its tight, I readjust it when this happens and it doesnt help...I am thinking I need to call Polar....
I have noticed that the machines at my YMCA pick up my HR from my strap, and this never misreads, while the watch still does....so it must be the watch right?

Also, it never misreads my HR when I am in exercise mode (1 push of the OK button) but when I go into Own Zone it starts acting up...

Very frustrating