The CTSlA is for most gas, oil, or electric healing/electric air conditioning systems The CT53A is for millivoltage heating systems. Do-it-yourself models CT5OA,C; CT51A; CT53A CPfilA shown YOUR NEW THERMOSTAT Your new Honeywell CT50A Heating Thermostat will replace most 15 to 30 V,2-wire heating system thermostats. The CT50A is suitable only for gas or oil heating systems (NOT for air conditioning, heating/air conditioning, heat pump or electric heating systems). Your new CT5OC Cooling Thermostat will replace most 15 to 30 V, 3-wire air conditioning system thermostats (NOT for heating, heating/air conditioning or heat pump systems). Your new CT51 A Heating/Cooling Thermostat will replace most 15 to 30 V, 4-wire. heating/ cooling system thermostats. The CT51A is suitable for gas, oil or electric heating/electric air conditioning systems (NOT for heat pumps). Your new CT53A Heating Thermostat is suitable for 250, 500or 750 millivolt (mV)heating systems only. PREPAI REMOL WIRE A TROUB Check thermostat procedures, please call a If you are unsure about wiring suitability lor your home’s qualified service technician for system by reviewing YOUR NEW assistance. THERMOSTAT section, above. FLAT BLADE SCREWDRIVER HAND OR POWER DRILL WITH 3/16 INCH DRILL BIT Proper installation of your new thermostat will occur WIRE CUTTER/STRIPPER and discard the if you follow instructions STEP- OR SHARP KNIFE under the cover. BY-STEP. It is recommended that as you read, understand and Save package of screws complete each step, you check and instruction pages. it off with pencil or pen. SPIRIT LEVEL OR PLUMB BOB AND LINE 11.95% anticipator adjustment Disconnect wires from old thermostat or subbase. If your thermostat has more than 2 wires, as you disconnect each wire, tape the end and label it with the letter of the terminal designation to make reconnection to new thermostat easier. Take care that these wires do not fall back into the wall opening. Keep the old thermostat for reference purposes until your new thermostat is functioning smoothly. WiRE AND MOUNT For CTSOA: Connect each rom the wall to either terminai on the back of the thermostat. Tighten the screws. For CT50C or Cf51A: Connect wires from the wall to matching terminals on back of thermostat. Tighten the screws. NOTE: If terminal designations on old thermostat do not match those on new thermostat, refer to chart below. system, and callnot Printed Printed REMOVING OLD THERMOSTAT If you have an electric furnace. you need to determine how your fan is controlled Turn it on and adjust your present thermostat so the heat comes on, while observing when the fan comes on If the fan comes on immediately you need to add the jumper noted in section 4 between terminals 1 & 2 If there is a noticeable delay before the fan comes on, there IS no need to add the jumper because your furnace controls the fan Begin by turning off power to the0heating/air conditioning system at the main fuse panel Most residential systems have a separate switch box or circuit breaker for disconnecting power to the furnace 0Remove cover of old thermostat- cover normally snaps off when - pulled firmly from the bottom If it resists. check for a screw that locks the cover on For CT50A or CTSIA installation 0before removing the old thermostat from the wall, look at it carefully to locate ihe heat 4 4 Recheck for level positioning, and firmly tighten both mounting screws CIyou Aave the If installing CTSOAor CT51 A, makssure turf-{anticipator setting) for your system. This is the number you wrote in the box in step 3 If you were unable to find the current draw for step 3. this information can be found printed on the primary control at the furnace. The primary control is usually agas valve, zonevalve, or a retay or burner controlbox with the thermostat wires connected to it. For electric heat, you need to add the :. n relay current, usually 0 2 to 0.4 A. ZONE VALVE OIL BURNER CONTROL SHOWS s LOW AGE CURRENT DRAW TO BURNER NT DRAVI TYPICAL GAS VALVE ii.iaic On the CT50A or CT51A, set heat anticipator indicator at rating printed on primary control. Adjuslablt, Hea' Ari c Set;[. I1- 0Press the thermostat cover firmly onto the mounting clips CHECK OUT THE THERMOSTAT To prevent possible com- pressor damage, do not operate air conditioning if outdoor temperature is below 50" F [lo0C]. Once the air conditioner is off, do not turn it on for 5 minutes: this action will prevent compressor damage. On the CT51A, the system switch controls as follows HEAT-heating system only operates. OFF-heating and air condi- tioning systems are dis- connected COOL-air conditioning sys- tem only operates. The fan switch controls as follows: AUTO-fan operates when heating or air conditioning system operates ON-fa rates co ousl NOTE In the following instruc- tion, disregard heating or air applicable toyour syst heating/air conditioning system Observe system operation for at feast one cycle on both heating and air conditioning. To observe. 0at HE...