Your thermostat or programmable thermostat is an integral part of your comfort system. These thermostats, whichever type you have, require little maintenance. Sometimes the only thing people know about their AC and Heating systems is how to turn the thermostat on and off and change the temperature setting.
A very common occurrence with service calls is the complaint that the thermostat isn't working properly. Sometimes this is true but most often it is something entirely different. Because some people believe the only problem with the system rests with the thermostat, they'll go down to the local hardware store and purchase a brand new thermostat. They get home and dust off the tool box, never read any directions, and proceed to change the thermostat. Some are successful and some are not. Those that are
most likely read some directions or had someone read the directions for them. The ones that are not successful end up calling a professional in to finish the job.
The bottom line advice to most people is to call a professional if something is wrong with your system. The problem may not be with the thermostat and you may exasperate the problem which will cost more in the long run. Additionally, If you have a multi-zone system, a high-efficiency heat pump or even just a heat pump, a regular split-system AC and a boiler for heat (and you have one thermostat), or an apollo based system (hot water heated in a water heater) with a split AC system, call a professional.
These systems can be very complex and may require special sub-bases so the control circuit will work properly. Additionally, for heat pumps, there are different controls, and wires for these controls run into the thermostat, they are multi-colored wires. These controls can be very complex and each wire must go to the correct terminal on the thermostat or the unit will not run correctly.
Additionally, be aware that thermostats are equipped with heating and cooling anticipators. Cooling anticipators are not adjustable where heat anticipators are adjustable in mechanical thermostats. Setting the heat anticipator is important for your heating system to function properly. It is set according to the amp draw on the control heating circuit. Make sure the heat anticipator is set properly so you will get the best out of your heating system.
The first thing you should do before changing the thermostat is to select the proper thermostat for your system. If you are retired or if someone is at home most of the time during the day you most likely do not need a programmable thermostat. If this is the case the only benefit you will get from a programmable is at night. Once you have made the selection you can proceed to the next step.
Thermostat Installation Advisory: If you decide to install your own thermostat you do so at your own risk. There are many incidences where the homeowner installed their own thermostat and were successful. There are also many incidences were the homeowner was unsuccessful. The ones that were unsuccessful wasted part of their day, ruined a thermostat or two, and caused the malfunction of an integral part of their system. That is not mentioning the fact that they ended up calling a professional HVAC Technician
to fix the problems caused by improperly installing a thermostat. The ones that are unsuccessful end up paying three to four times what they would have paid had they called a professional in the first place. Factor this in to your decision and if there is any doubt call a professional to install the new thermostat.
* Get the tools together that you will need to do the job right. You will need:
o A small straight-slot (or flathead) screw driver
o A small phillips screw driver
o A pair of needle nose pliers
o A utility knife or wire strippers (for small wire)
o Plastic wall anchors (sometimes provided with the thermostat)
o A drill with a bit to make the holes for the plastic wall anchors
o A small level
o Two pencils or pens
o A small paper bag and some masking tape (tape the bag below the area where the thermostat is so that any trash or dust will fall into the bag and not onto the floor)
o Some touch up paint
o Clean hands (don't do a great job changing the thermostat and leave all those prints all over the wall)
o Plenty of light
* Turn the power off to the unit at the circuit breaker or the emergency cutoff switch. After doing that make sure the power is off by turning the thermostat to the on position and going to the unit to make sure it is not on. Not all circuit breakers are labeled correctly and not all emergency switches are hooked up. Just make double sure that you have killed power to the unit not only for your safety but also to keep from blowing the transformer.
* Pull the cover off the front of the thermostat. If it is a mechanical thermostat there should be a little adjuster tab in the center of it. This is your heat anticipator. It should have numbers ranging from 1.5 to .1. Take note of this setting and remember to set the new thermostat to this same setting if you are replacing a mechanical thermostat with another mechanical thermostat. You probably want to do this now before you proceed further. If you are replacing a mechanical with a digital, the digital
should set itself automatically. If not read the instructions on the new thermostat for instructions on how to set the anticipator. This is very important. An improperly set anticipator will cause your heater to run improperly. The thermostat is also equipped with a cooling anticipator. Cooling anticipators are most often on the sub-base and are non-adjustable.
* Unscrew the thermostat from the sub-base. Take note of each wire. The following list should match the wires and terminals on your thermostat.
o Red to the RH or RC terminal with a jumper wire between RH and RC. Or Red to the R terminal which is shared with both the heating and cooling. It has an internal jumper built in to the sub-base. The red wire is the hot wire. All other wires are common wires.
o Green to the G terminal. This is for the fan.
o Yellow to the Y terminal. This is for air conditioning.
o White to the W terminal. This is for heating.
These are the four wires that you need to control the heat, cooling and the fan. If the colors of the wires do not match the colors described here make sure you mark the wires with masking tape. If there are more wires that are not hooked up don't worry. This is common. Thermostat wire comes in many different varieties and the contractor who installed the system probably used 5 wire or 8 wire thermostat wire. They used what they needed and simply twisted or cut the other wires off.
* Remove the wires from the terminals on the sub-base. The power should be off so you shouldn't have to worry about being shocked. Be careful not to let the wires fall back into the wall. Sometimes there is just enough wire to reach the terminals and that's it. Try pulling the wires a bit to see if there is more wire behind the wall. Most of the time there is some slack and you can pull the wire out more. Unscrew the sub-base from the wall while holding the wires. When you get the sub-base off wrap the
wires around the pencil or pen. This will keep the wires from falling back into the wall.
* Get the new sub-base and compare it to the old one. Hold it up to the wall in the position you want it. Is the old paint that was covered by the old sub-base going to be covered by the new sub-base? If any of the old paint is going to show you may want to make some touch ups now. After finishing with that, put the new sub-base back on the wall in the position you want it. Make sure it is as level as possible. You can use a level to do this. (This is very important especially for mechanical thermostats.
It must be level or the mercury switch will not keep the proper temperature settings in the house. Make sure it is level.) Mark the new holes through the sub-base where the screws will go into the wall to fasten the sub-base.
* It is important in this step to have the proper drill bit size for the size of wall anchors you have. Some wall anchor kits come with a bit in them. We recommend the wall anchor kits with the bits in them because it is the perfect size drill bit for the anchors. The bit should be slightly smaller than the anchor. If the bit is bigger the wall anchor will not hold and the possibility exists that the thermostat will fall off the wall. Drill the mounting holes you made for mounting the sub-base. Insert
the wall anchors and push them hard with your thumb. Approximately 1/16th of an inch on the lip of the anchor will remain sticking out of the hole. If it is more than that use the butt-end of the screw driver and push it in until just the lip of the anchor remains visible.
* Undo the wires from the pencil or pen and run them through the center of the sub-base. Insert the screws and screw them only snug tight. Get the level and make sure the sub-base is level. When you are sure that it is level, tighten the screws. Be careful not to allow the sub-base to move when you are tightening the screws.
* Using the color code of the wires (or if they didn't match, the color markings you made with masking tape), attach each wire to their proper terminal. Some people like to loop the wire around the terminal screws. This is not necessary. What is necessary is that the wires are attached to the terminals and they are tight. Additionally, make sure that none of the bare wire is touching anything except the terminal. Once the wires are attached you are almost finished completing the task of installing the
thermostat. The hard part is over!
* Attach the thermostat to the sub-base. The screws for this are built in the the thermostat. Tighten these screws and check to make sure the heat anticipator is set to the same setting as the old anticipator setting.
* Attach the front cover to the thermostat and restore power. Start and check the heating, air conditioning, and with the heating and air conditioning off, the fan only sequence. All systems should be working properly at this time (if you did the task properly) and you are the proud owner of a brand new, properly installed thermostat.
Programmable thermostats can save you more than ten percent on your homes utility bills. For that reason a programmable can pay for itself within a few years depending on the type and expense of the type you purchase. Among others, you can expect good quality from Honeywell products. If you are or someone else is at home most of the day and night, you most likely do not need a programmable. Programmables are designed for the family on a regular schedule. Those that wake at a certain time, leave the
home at a certain time, return at a certain time, and go to bed at a certain time (on a regular basis), will benefit from a programmable thermostat. Read the following information and see if it applies to you for your benefit.
How the programmable thermostat works
You have four settings on the programmable thermostat.
* Wake - this is the setting you want the temperature to be at when you wake. If you wake at 6 a.m. you probably want to set the wake time and temperature for 5:30 a.m. and whatever the desired temperature is for you.
* Leave - this is the time the last person leaves the home for the day. If that person usually leaves at 8 a.m. then the thermostat can be set to change the temperature at 7:30 a.m.
* Return - this is the time that the first person arrives home for the day. If that person arrives home at 4 p.m. then the time and temperature can be set at 3:30 p.m. That way when the person arrives home, the home is at the desired temperature.
* Sleep - this is the time when everyone goes to bed for the night. If everyone is in bed by 10:00 p.m. then the thermostat can be set to change the temperature to a lower setting for the night.
Most programmable thermostats have settings for both the weekdays and weekends so on Saturday and Sunday you can tailor the settings according to your comfort level and usual schedule for those days. All of them have options to over-ride the program for manual settings and an additional benefit to owning a programmable is that most are equipped with a compressor delay to protect your compressor from short cycling.
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