I have a couple stacks of 421D cages. I just noticed one cage doesnt seem to keep its temp no matter how high I raise the thermostat. I cant seem to get the hot side more then 82 and cold side is always low 70s. I was wondering if anyone has ever had any problems like this and if it could be flexwatt going out this cage is about 7yrs old I believe and if thats the case how long does 11" flexwatt normally last? The cage is the bottom cage on the stack however my other stacks even bottom cage has no heating problem. Thank you for any input





