I used Glad plug ins for years without problems either. I unplugged all of them when the peeing started because I had read an article that sometimes other strong scents may cause a cat to mark.
Our distributor sent the new replacements today. I just plugged in one and it's not as hot as the others but still much warmer than I'd care for on a plastic object. I figure I'll just only plug them in when I'm here and unplug them when I'm gone or going to sleep. I'm sure this won't be as effective, but it's got to be better than nothing, and certainly a bit safer than just leaving them plugged in. When I plugged it in the cats came sniffing around within minutes. I can't really smell anything, but obviously they do.
On a side note I've been noticing the Feliway plug in's at the pet stores are made by a different company than the ones I have. The pet store ones are made by a US company called Farnam (or something similar) and the ones I have are made in France by Ceva. I'm wondering if that has anything to do with all this? I'm reluctant to try the pet store versions because I get my diffusers with one included vial for $21 at work (refills are $12), the pet store ones are $36 even with a coupon!! I'd hate to spend the extra money to find out they all are the same.
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