DavidAndKasie is correct. Heat pumps CAN be set back (turned down) effectively with a setback thermostat that has smart recovery. First, since you say that you don't understand much about how heat pumps work, let's cover that. A heat pump basically is the same as an ordinary airconditioner, with the addition of a reversing valve that changes its functioning to HEAT the indoors instead of cooling. Air conditioners don't so much MAKE cold as they MOVE heat from one place to another. In cooling mode, heat is moved from inside to outside. That's the hot air you feel blowing from the unit outside (the inside blows cool air). In heating mode, the unit picks up heat from outside and moves it IN (the outside unit blows COLD air, the inside WARM). There technically is heat in the air (or an object) down to scientific absolute zero (-459.67F) when molecular motion stops. It's cheaper from an electric energy expenditure point-of-view to MOVE heat than to CREATE heat. Thus heat pumps are cheaper to operate electrically than glowing-red heating elements. However, when the outdoor temperature drops, particularly to the point of ice/frosting, it's harder for the heat pump to pick up the heat and move it inside. So all heat pump system have an auxiliary heat source, typically standard electric heating elements, that activate as needed when it can't maintain the desired indoor temperature without help. This is called the "balance point" -- the point at which the heat pump can't move heat in fast enough from outside to counteract the heat loss that's occurring through doors, windows, walls, etc. Every system and house is different in that respect. The indoor temp drops below the setpoint (thermostat set on 70°F, room temp is 68°F for example), and a 2nd pair of contacts trigger in the thermostat which turns on the heating elements. Electronic thermostats may also do this based on time. If the system can't reach the setpoint (70°F) within a specific time period, or the thermostat senses that the indoor temperature isn't increasing or isn't increasing fast enough, the elements turn on. Of course, the heating elements pull a lot more electricity and aren't as efficient as the heat pump. So the trick after a setback (or having turned the system completely off) is to raise the temperature SLOWLY so the heating elements DON'T turn on. Electronic setback thermostats designed for heat pumps do this automatically. The computer figures out how soon to start the recovery process so it can raise the temp slowly and hit the target at the specified time without using the auxiliary elements (or minimizing use of them). It may take a few cycles for the computer to "learn" the characteristics of a particular system and get the timing right. You can also do it manually, but you have to PAY ATTENTION and not raise the temp too fast or too high at a time. This may take a couple hours at lower outdoor temps. Beware also that if the outdoor temp is well below the aforementioned "balance point" the system may NOT be able to recover the desired indoor temp at all without use of the auxiliary heating elements. Another aspect of heat pumps that you should know about is defrosting. As mentioned earlier, the outdoor unit in heating mode is basically cooling the outside. During some conditions, particularly wet/freezing weather, the coils can ice-up, like a food freezer that needs defrosting. Air can't blow through the coils when they're clogged with ice, so like a freezer they must be defrosted. The system does that by switching back to AIR CONDITIONING mode for a few mins so the outside coils get warm and melt the ice. Now remember that when running as an air conditioner, the system blows COLD air inside the house. During defrost, the auxiliary heating elements turn on, NOT for the purpose of melting the ice on the coils outside, but to warm up the cold air that would otherwise be blowing in the house. There's no way to prevent defrost from happening, the system does that automatically as needed. Some people say that if the outdoor temp is so low for an extended period that the system is running continuously, the outdoor unit is repeatedly icing over and defrosting, then it's best to set the thermostat to Emergency Heat, which shuts off the heat pump and runs ONLY the heating elements ... since they're being used a lot anyway during the frequent defrost cycles.

I hear you ladies........since I've hit 40, I first had my gall bladder removed. Then a year ago, I had a bladder suspension, now I'm trying to deal with my lifelong endometriosis and cyst pain. I spot bleed on and off all month. The loss of hair on your head and additional hair on the face is no picnic........... But.....if we had lived just a century ago, we would really be in "Old Age", nearing the end of our lives. The good thing is, that we really are still young enough to enjoy our families and choices that we've made in life. Even with all the nuisances of mid-life, I wouldn't change and go back 30 years. Nothing comes easy.....getting where you are today didn't come easy...I have a philosophy that our bodies break down as we age, we become dependant (somewhat) on our families and on God, and leave this world in the same condition that we came.......there is a lesson in it, it's up to us to get it......trials, blessings, the whole package of life.

Rina - these plants and some other tropical succulents are very temperature sensitive. Although my apartment probably won't get colder than 65 degrees F, I'm worried that the draft from the windows will make it colder, especially in like January or February when it get bitterly cold here. Minty - the indoor temps would be at least 65+, but for a lot of Somalian and Soqotran succulents, that is literally the lowest advisable temperature I have seen on the internet. I would probably want to put all my Dorstenias (gigas, lavrani, foetida, barnimiana, cuspidata, and zanzibarica), all my Pseudolithos (2xcubiformis, dodsoniana, miguirtinus), some of my other Asclepiads (Whitesloanea crassa, Stapelianthus madagascariensis and decaryi, Echidnopsis specksii) and a few Malagasy Euphorbs (tulearensis, bongolavensis, cylindrifolia var. tubifera, maybe a few more small species) on the heat mats. cactus - yeah, these species are kind of tricky that way! their winter is more of a dry mild warm season that a cold one. I think you're right, I wouldn't want to give like 80 degree bottom heat during winter, but I've been reading online and some people say that keeping their root zones around at least 70 degrees can help these plants survive the winter more easily dog - thanks for the info!! your gigas is beautiful :-) i see you have some D. lavranis heating up as well! if you don't mind me asking, does running the heat mat during winter raise your electric bill a lot? you can PM me about it if you like, or you don't have to answer if that's too personal!

Get a new thermostat. One that isn't so dang complicated. Hate programmable ones. If I want it a certain temp I just change it once instead of having to change it for every day and time of the week. Also, the model you have has lots of bad reviews for going faulty. I have one of these non-programmable. Works great. Put it on auto and heat or auto and cool and set it to the temp you want. Turning it off is easy as well. Can usually get this one locally if you don't want to wait for online order.