How long do they last ?
765648
I put new ones in about a year ago, our house was build in 2004 and it seemed that the "contractor grade" air vents were what you would expect. So far the new ones seem to work okay without any problems.
976151
They seem to last for a long time. I did not see any spots on them and I have had them for a couple of months. After this weekend, they are all gone.
1776586
So far they have lasted about 6 months. As to buying locally, I haven't found any store that sells them.
1111056
I would say a few weeks, depending where you put them. If you have them in a rather air-tight container, they last a very long time...if there is air exchange, they obviously won't last as long. I like them a lot but I did have one go bad on me...when I was re-charging...for some odd reason, the balls turned black...rendering that one useless...the others that were in the same condition and were heated for the same time did just fine...
953543
MIne are lasting quite a long time. Sseveral years and on for as much as 12 hrs per day.
360310
I've had mine about a year, use them every day for at least 3 or 4 hours. Still perfect.
417654
don't know. When I buy them they are usually good for 6 to 12 months or longer.
950683
Don't know, I haven't had to replace them. But it's my understanding they last or thousands of hours.
1110826
Depends if you purchased New or Old or Refurbished or so.They do last 3-5 years depending on how well they are looked after.
354437
I believe they don't have an expiration on them. They seem to last forever.
2259949
At least a few months. I use them too quickly to find out, but I used a leftover box after about three months and they were good as new.
1664617
There is a little variation with some but, on average, I would say about three weeks. I've used them for about a year in two separate locations in the house. Hope this helps.
1036655
Exactly 167 years, 5 months, 28 days, 4 hours, 37 minutes.I'm kidding. I have no idea, but it would seem that with proper care they should last a few years. :)
372036
I have used these for about 4 years. They have been lasting close to 1.5 years. I have had no problems.
540335
They're good for about three years. They only last about a week so that's plenty of time.
333015
They last a long time, I have some from a year ago. Of course one or two of them may not last, but over all they are good.
76930
I've had them and use for over 6 months and they still operate. How long they will continue to work is anyone's guess.