only gave it 4 stars since I just got it and don't know, but so far it is great, hot, too hot for me but hubby loves it, strong, I sit outside on it and just put my legs and feet in it, cool lights, cool waterfall, so no one panics the jets go on and off automatically when it is heating up, they won't shut off until it is at the temp you set, then go on and off as needed to keep it at the right temp, seems to hold the heat good too but it has only been down to 50 so we shall see, so far we love it!