Heat Pumps and Electric Heating - Programmable Thermostat with Hot Water Backup Heat

We get a special "off peak" rate. Water tanks are heated at night, and that serves as the back up heat source when the heat pump needs more heat than the air can provide.
When we got the system, our electric company told us not to use a programmable thermostat on the argument that it cost more to raise the temperature than to keep it constant. Is this a valid argument? What if we are keeping the temp at 60 degrees for 16 hrs. of the day? It's hard to believe that doesn't save money over keeping the same temp.

Assuming it IS cheaper to set it back, what is a good thermostat to use, given the fact that the back up hot water tanks are only heated between 5 pm and 7 am?

Phil

Yeah you hear that a lot about the setback t-stats and obviously there are a lot of factors at play to determine the break even point of a setback. If you have a solid 16hrs out of 24hrs that you do not require the higher temps I would use a setback maybe even go 10 degrees a bit of experimenting may be required since factors such as building envelope integrity/mean temps of your area/equipment efficeincy may greatly affect your results. My main area of concern was none of those however since my wife is very fond of tropical houseplants the temp has to stay steady and warm AARRGGHH these silly plants cost me a fortune. The key is that the 16hrs must be a continuos period of time where the setback is used, if for instance you are repeatedly bringing the temp up every few hours you will find very little savings and actually may loose. I like the Honeywell t-stat's a nice 6000 series would probably fix U right up.