Since the Chronotherm III thermostat hasn't been produced since 1998 or before,
		all the supplies on the shelves may have been depleted. One option I
		have suggested is that if you just must replace it with an old Chronotherm III,
		and the only one left that will do the job is the T8601C1021 or some 
		other one similar, it may require an additional wire that the old one 
		did not need.  You may have an extra one in the bundle of wires that 
		come from the wall. You connect it to the C terminal on the thermostat 
		and then in the furnace connect the other end of it to the C terminal 
		there. This is a wire that connects the other side of the transformer 
		voltage to the thermostat. It won't work without it.
		
		If you don't have a spare wire, then you have to run one to the 
		thermostat and heater.  Maybe this would be easy or maybe it would 
		be nearly impossible. You decide.
		
		However, if you don't mind new technology and you want the 
		current production (and better) model and don't want the hassle 
		of trying to run an extra wire, then you need to look at the 
		Honeywell® VisionPro™ which is the replacement for obsolete 
		Chronotherm III or IV thermostats.
		
		
		 ¹

        Honeywell® VisionPro
Replacement for obsolete Chronotherm III/IV
        
        You can do it yourself.  Your old thermostat may have terminals 
        W,G,R,Rc and Y.  The new VisionPRO™ has terminals that match 
        that exactly. If you have the Chronotherm III, just remove the two 
        screws on the front of the thermostat. You can then lift off the 
        front part of it. While you have the front part off the wall, make 
        a note of the wires that come out of the wall and to which 
        terminals they attach. Ignore the terminals that do not have wires 
        attached that come through the wall.
        
        You just unplug your heater or turn off the 240 Vac or 125 Vac 
        to the heater and the electricity to the thermostat will be "dead".  
        Remove the old thermostat and the subbase off the wall and set it 
        aside. 
        
        Mount the new subbase and attach the W,G,R,Rc and Y, etc. to 
        the same terminals.  One thing to look for, if your old thermostat 
        had a jumper wire between the R and Rc terminal, then you leave the 
        jumper (factory installed) in place on the new thermostat.  If there 
        was no jumper on the old thermostat between R and Rc, then you 
        remove the jumper that is in place on the new thermostat also.
        
        The new thermostat will operate on battery power alone if you 
        do not have the C terminal connected to a wire.  Hundreds of 
        thousands of them (including mine) are doing it very successfully 
        already. It is not a problem.
        
        You will, however, need to do something new.  You must set 
        the "Installation Options" in an "installer options menu" 
        in the new VisionPRO™ thermostat.  It is not difficult and 
        if while you are doing it you have questions, then you can always 
        call me and I will walk you through it. I don't mind. I am 
        central time and am available from 8:00 AM until about 10:00 PM daily. 
        

        All the information is shown in a booklet that comes with 
        the new thermostat. It even shows pictures of where to place 
        your finger on the thermostat.  All you have to do is follow 
        instructions and if you falter, call me.
        
        One marvelous new thing about the new thermostat is that 
        you can set it so it will show not only Heat, OFF, Cool, but 
        it can be set to show Heat, Off, Cool and Automatic changeover 
        from HEAT to COOLING and vice versa.  This is wonderful. The 
        only problem you will have because of it is that you now will 
        never know what the temperature is outdoors.  Your home will 
        perpetually be comfortable.
        
        Here are some of the features of the new VisionPRO 
        thermostat that you might want to set:
        
        *  You will set the options to the correct year, 
        month, day and time.
        
        *  Then choose 1 heat/ 1 cool (it is already 
        factory default set to this one)
        
        *  You can set the temperature limits on the 
        heating and cooling.  You could set it, for example, so that 
        no one could accidentally set the heat to 90° F and leave 
        it. You could also set the cooling to 68° F 
        (or something else) so that no one could set it below 68°F.
        
        *  You can even set it so that no one but you has 
        access to the settings.  You could allow others to only have access to 
        Temporary Temperature changes, but not to the program settings.
        
        *  You can select individual 7 day programs. You 
        can even choose to allow all four program periods as you had 
        before or reduce it to just two per day. It uses Wake, Leave, 
        Return and Sleep just as you had before on the Chronotherm III.
        
        *  You can set an option to remind you when to change 
        or clean your filter, UV light, or when humidifier pad replacement 
        is needed.
        
        You don't have to set any of the things above if you 
        don't want to. I would suggest you do set the calendar and 
        time and set the system to have automatic changeover.
        
        The automatic changeover from heat to cool or vice versa 
        is so good. You will find that you never know what the temperature 
        is outside because your house is perpetually comfortable regardless 
        of conditions outside.  You never wake up to a cold floor again.
        
        Options available for the new VisionPRO:
        
        *  Remote room temperature sensors. You can have 
        up to 12 of them—one in each room. It will average all of the 
        temperatures and run the system accordingly.
        
        *  Remote outdoor temperature. This will allow 
        the outdoor temperature to be displayed right on the face of 
        the thermostat at all times.
        
        * NOTE: Both of the two options above require wires 
        to be run to each device.