Outdoor thermostat-How and when to use them?


If you have a heat pump in your house you probably have heard of the name outdoor thermostat.Why? Well as you probably know that not all indoor thermostats are made for heat pumps and even if it is you may have problems in winter when you either want your supplemental heat to turn on when outside temperature falls below tripping point.Or you want to not allow supplemental heating to turn on unless it is below certain point.This is where you can install an outdoor thermostat.



Outdoor thermostats are mechanical thermostat switches that senses outside temperature and can be installed in conjunction with your present indoor thermostat.Its purpose is to cutoff compressor and bring on the auxiliary heat when temperature falls below a point at which your heat pump is no longer effective in meeting the load requirement of house.

Conversely it can also be used to keep auxiliary heat from starting unless temperature is below a  set point band thus maximize efficiency.

Modern programmable thermostat do come with special algorithmic time delay to do this by sensing outdoor temperature with an outdoor sensor like Honeywell vision pro thermostat but in case you have basic heat pump thermostat and want to add an extra level of control an outdoor thermostat can do that job for you.


A heat pump is designed like an air conditioner with most part like condenser evaporator etc common to Ac system except that it can transfer heat both ways. When functioning like AC it takes inside heat to outside. But when functioning in heating mode it does the reverse by squeezing heat from outside and bringing it inside.It does it with a 4 way reverse valve.



During winter the air outside is cold so there is limited capacity up to which the heat pump can work efficiently.

So there is a provision of auxiliary heat.This heat comes into play when there is more than 2 degree difference in ambient temperature and set point and also when the load capacity of heat pump is less than load

This heat can come from a electric heat strip or a furnace. System that uses furnace as auxiliary heat are called dual fuel system.

One mistake that people do with heat pumps is that they switch on auxiliary heat but turn off the compressor or heat pump when outside temperature falls below certain point. In this mode the heat pump is running in emergency heat mode and not supplemental heat mode.

Most heat pump have electric resistance wire as auxiliary heat source which is very costly in terms of producing heat. So running the heat pump on supplemental heat alone greatly increase your electricity bill.

Best practice is to keep the heat pump running but add supplemental heat to make for the load demand that the heat pump is not able to meet up.



From above graph you can see that around 30 there is a balance point between load and capacity of heat pump. Below that temp the capacity is lower than the load of the house but it is not zero. So turning off heat pump condenser completely is not effective way of running a heat pump.


For Compressor cutoff-Although it is not recommended to completely cutoff the  the mechanical heating sometimes it is desired because low temperature can cause many defrost cycle or to shutoff the noise when its relatively less efficient. But overall it should be avoided.

For Heat holdoff-In this mode the thermostat prevent the supply of supplemental heat which is costly and will only allow if outside temperature is below certain point. This is better way of using outdoor thermostat.




Many thermostat like Honeywell vision pro, Honewell T10, Goodman Comfortnet CTK04AE thermostat , Honeywell thermostats with truezone panel etc and countless others can sense the outdoor temperature and also comes with an internal algorithms to switch between the dual fuel or electric and mechanical heating as stated in the starting of the article. Keep in mind that some thermostat like Honeywell 9000 series can use weather forecast to sense the outdoor temperature by ntering your local zip code into the system so the use of a temperature sensor is not required.

For these type of thermostats there are certain sensors that can do the job. You just have do install it at the location where you want to sense the ambient outdoor temperature and the thermostat will decide based on the setpoint to run the Auxilaary heating lockout or Compressor lockout based on the mode of operation.

Two such popular temperature sensor are

1.Honeywell C7089R1013 Wireless Outdoor Sensor

This sensor is made for wireless Honeywell thermostats. It comes with upto 5 years lasting 2AA lithium batteries. It pairs easily with Honeywell thermostat like Vision pro 8000. You need to have a Honeywell thermostat with Red link capacity. Although the sensor uses wireless communication for transmission it doesn’t interfere with the other wireless instruments around it.

You can add this device in your thermostat using the installer code of the product. It can gather both temperature and humidity information of its surroundings. You can use it compressor lockout like at low temperature where auxiliary heat kicks in and auxiliary heat lock out at higher temperature when it shuts of the auxiliary heat. You can use the humidity and temperature reading to control the humidity inside by locking out the vent when dew point is above certain level.

Some user find the temperature to be wrongly calibrated like around 6 degree so you can check and make adjustment or it will not give efficient performance when used for thermostat functions. Also one sensor can be used to read temperature in more than one thermostat units if you require.Be sure to install it under a shade at the north side of the house as it is sensitive to the sun.

Here is a link to the manual of the product.


Click here for more reviews rating and price of Honeywell C7089R1013 sensor

2.Honeywell C7089U1006 Outdoor Temperature Sensor

This light weight wired temperature sensor comes with a 2.25 x 0.375 inch sensor head with 60 inch lead wires wihich can be stretched to maximum of 200 feet by adding more length to it using 18 gauge 24 V thermostat wire. There is a mounting clip that allows for easy fit on siding or soffit. The listed accuracy of the +- 1 degree F at 70 degrees F.

It works with Honeywell Honeywell Th8000 – TH 7000 series. However it can not be used with the RTh series as it uses wifi to retrieve outside temperature. Its works well with heat pumps and dual fuel systems. It is sensitive to the sun so try to install it under a shade.

Click here for more reviews rating and price of Honeywell C7089U1006 Sensor


Well outdoor thermostat are not that much required with modern new thermostats having the ability to sense outdoor temp and optimizing the efficiency. But they are still good additional switch that will ensure your system heat cutoff and cut in capabilities.

Switch types

But first I think you should know various electronic switch code that are common with these thermostats.



stands for Single pole single throw which is just a simple on-OFF  the switch has it has a single pole which when thrown(makes contact) conducts otherwise it breaks the circuit.



In this type of switch is single pole connected to common toggles between two position which are both conducting, ie completes a circuit.

TPI LB110 Series LB Bi-Metal in-Built Thermostat, SPST Heat Only


TPI is American company which manufactures heating, ventilation, lighting, thermostats and and replacement heating element .

This thermostat has a bi metal temperature sensor instead of thermocouple. Comes with 6 feet/4 Gauge of lead for installation.

TPI LRD100A Series LR Bi-Metal SPDT Outdoor Thermostat


It also has a bimetallic temperature sensor with temperature marking in steps of 20 degree. Comes with 6 Feet/14 gauge lead for installation. It is dual switch which can toggle in two position of On. If not in use one terminal can be connected to common.

Goodman Outdoor Thermostat Kit OT18-60A

Goodman company which manufactures furnace, AC, Heat pumps and also HVAC replacement components.

This set is also a complete kit for installation. Temperature sensor is thermocouple and temperature marking in multiple of 5.

Following models of outdoor thermostat are available for purchase on amazon.

OT18-60A – Janitrol OEM Replacement Heat Pump Outdoor Thermostat


This is a replacement kit for heat pumps thermostats from Janitrol which was acquired by Goodman. It also make furnace, Ac, heatpump and HVAC replacement parts. This thermostat has a thermocouple lead as temperature sensor .You would need power tools and maybe a handyman too.

Best wifi thermostat with humidity control


When you think of humidity what comes to mind.Mist ,fog,dew,wetness.Well all these conventional picture of humidity tells that it is related to amount of moisture in the air.But our comfort level is not just related to moisture present in the air.A more important and useful term is relative humidity and temperature that affects our level of comfort inside our house or outside.When accessing IAQ(Indoor air quality) both these factor must be taken into account.

So what is relative humidity(RH)?

Well in simple terms it is the amount of moisture present per cubic meter of air.Now while the volume of given air remains fixed the number of molecules of  air,in other words how dense the air is depends on the temperature of the air.Now obviously dense air which is colder can hold less moisture than hot air because as air expands when heated there is more space between molecules in hot air to accommodate water molecules than in colder air

So if we take air of fixed amount of moisture content in it and heat it its RH will decrease  and if we cool it RH will increase.You can test it by measuring RH at inlet and outlet of your furnace or AC respectively.

But there is a paradoxical effect seen in weather conditions.

You may have seen that hotter seasons are high in humidity while colder seasons are dry.This is because it generally rains or water evaporates faster in hot season so no of water molecules per cubic meter of air is higher than is in winter.

While in winter the air saturates and the water condenses to form droplets or ice.But we don’t see droplets forming on window panes in summer.

We know that AC coil takes up the latent heat from water vapor molecules and removes moisture and but it increases RH.It is only when this cool air mixes with indoor hot air that the RH of supply air decreases while of whole house increases.

Similarly a furnace makes the air less dense so reduces RH of supply air but when it mixes with the colder air of whole house the RH of supply increases while of whole house decreases.

How humidity affects us.

High humidity levels in the home creates allows for growth of for mold ,dust mites,powerful allergens and irritants which is not good especially for people with asthma.

On the other hand if humidity is below 30%,

  • It causes irritation of the mucous membranes in nose and throat, leading to  breathing difficulties.
  • Dry air is adds to discomfort to people with skin or eye conditions.
  • It is also dry wood made items them too much creating cracks in them.


HVAC components that control your indoor humidity.

Whole house Humidifier-Used in winter season.Introduces water molecules into the draft air by intake from a solenoid valve and pouring it on a meshed plate.The water evaporates and is then taken away by the air draft on the duct it is installed.

Dehumidifier-Can be used in extension to AC.Work almost like AC but do not cool the air but help in making you cool since it removes the stickiness and mugginess from air so your sweat evaporates faster and make you feel cool.

Dehumidity-stat-It is a simple device that operates and control the dehumidifier or AC But it is more used for energy saving device when you are gone for extended period of time or vacation rather than humidity control and prevent growth of mold or mildew inside your home.

The setting of the nob is like follow.

In summer

When Away-Set the Knob(Used for dehumidification) to 60 % and temperature your desired cooling temperature Ex-80 degree F and set your fan switch to auto.When away your thermostat wont work if humidity is less than 60% but dehumidifier would.

When Home-Set the Knob to about 100% and operate the thermostat normally.

control(that lets water in to the humidifier) valve to humidify(when connected to humidifier) or dehumidify(when connected to dehumidifier).

Check out popular humidifier on amazon.


In winter

This humiditistat comes with the company making your whole house humidifier.In winter when humidity is low Set the humidistat knob to 55 % which in summer would have been in off position.Also you need to adjust the humidity level according to the temperature outside to prevent formation of dew on windows etc and dry the house furniture or wood work beyond acceptable limits.However people generally forget to change it from time to to time.

An alternative to all this could be a humidity controlling thermostat which can control both humidifier or dehumidifier according to the weather and RH present outside.Below we have listed some good wifi thermostat with humidity control feature that is easy to set and forget type.

1.)Honeywell YTHX9421R5101WW/U Prestige IAQ Kit with Redlink technology


Although this thermostat is not programmable it is a full on solution for your indoor air quality including temperature and humidity.It comes with multiple temperature and humidity wireless sensor that you can install inside or outside home and based on inside and outside reading it will smartly adjust your AC or dehumidifier or Humidifier.It says DIY type but it is recommended to install it through professionals.

Check out Honeywell prestige IAQ kit on Amazon.

Other than that it uses red link technology by Honeywell which is secure and reliable in terms of communication between devices.Here is a video explaining Red link technology.


2.)Aprilaire 8620W WiFi Thermostat

Aprilaire is an HVAC manufcacturer that makes humidifiers,dehumidifiers air purifiers,home automation using zoned temperature control and of course thermostats.The above model of Aprilaire thermostat can control both your humidifier and your dehumidifier from the thermostat itself.Along with humidity it also has event based air cleaning and ventilation controls.It has an auto mode which allows you to control humidity hands free.

Temperature we feel is also a affected by humidity so if you can control that with other parameter other than heating and cooling it can lower your energy cost. At least that is what the company claims.In all it is a decent thermostat that allows auto humidity control.

Check out more reviews price and ratings of  prilaire 8620W WiFi Thermostat on amazon.


3.)Venstar T7900 Programmable WiFi Thermostat


Venstar is a US based company which exclusively makes thermostats for residential and commercial use and energy management system for small businesses. The above model is T7900 which is only residential model with humidity control humidifier and dehumidifier. It has color touch screen which also allows you to set wallpapers and sd card into the Thermostat.You can add voice control by connecting Alexa device.(only).You set the humidity set point and it will humidify using humidifiers or dehumidify using cooling mode.It also auto adjust recovery time using changing seasonal trend.It calls it smart recovery.Overall its a little pricey but good addition to add to your comfort level.

Click here for more rating reviews and price of Ventar T7900 wifi thermostat on Amazon.

4.)Honeywell TH9320WF5003 Wi-Fi Touch Screen Programmable Thermostat

Also called Honeywell vision pro 9000 this thermostat is an upgrade to vision pro 8000 which also have wifi and humidity control for humidifier and dehumidifier in auto mode.The same design type model is RTH9580WF. The difference is that later is a smart thermostat with auto adjust feature like nest or Ecobee. But with price consideration you may be quite satisfied with the above model.It comes for around $140 in comparison to RTH9580WF which is about $230.

Click here for more rating reviews and price of Honeywell TH9320WF5003 Wi-Fi wifi thermostat on Amazon.

The setting for humidity control is quite easy.

In summer months.

1.)Go to Menu>Select Humidification>Goto help to know how each setting works>Seleect dehumidification>Set your humidity level to about 60%>Select done and go back to home screen.

In winter months

Got to Menu>Scroll down to find humidification>Click on help meny know how different setting works>Set humidity to about 35 %>Tap on done and go back to home screen.

Your system ability to reach that humidity in winter or summer will depend on outdoor temperature and humidity and also on your home age structure and insulation levels.

5.)Ecobee3 smart thermostat


Ecobee 3 is the middle ground in the whole range of ecobee smart thermostat interms of price and features.But it has what you need.That is ability to control humidifier or dehumidifier uses its ACC+/ACC-  terminals to control any other accessory other than heating or cooling.In summer moth you can adjust humidity by setting the humidity set point and also AC over cool max setting so you don’t over run Ac to lower the humidity.

For winter moths it has a frost control which lowers humidity set point as the outside temperature falls.This prevent frost on windows and save them from damage.

Check out more reviews ratings and price of Ecobee 3 lite smart thermostat in Amazon.

Here is a video how to set humidity in summer .Setting in winter will go along the similar process and or you can refer your manual.

6.)Nest smart thermostat-When it comes to thermostat we know nest is the market leader.It comes with almost all feature you need in a thermostat.Only drwback is that it is not cheap and maybe not for everybody if you dont need most of its other feature like geofencing etc basically what makes it a smart thermostat.

In Nest controlling humidity after wiring is just as simple as setting the humidity set point and over.You will be done. It will start controlling your Ac dehumidifier or humidifier according to your humidity set point.See i this video.

Check out more reviews,price and rating of nest smart thermostat on amazon.

7.)Cielo Breez Plus, Smart Air Conditioner Remote Controller


This probably a new entrant into thermostat market is meant only for those who suffer from hot and humid climate.Its is cost effective way of controlling Ac to keep temperature as well as humidity into your desired range.Works with most of the Ac brands and models and is also compatible with Alexa and Google assistant. It also has Geofencing. However if you want to control your Furnace or humidity in winter as well this is totally not the thermostat you need.Other than that it has overall good customer feedback and ratings.

Check out more reviews price ratings of Cielo Breez Plus, Smart Ac thermostat on Amazon.

Honeywell RTH7500D Review

Perhaps more than any other company, household thermostats are most commonly associated with Honeywell, the brand whose history reaches back to the invention of a coal thermostat in 1855. Honeywell’s line of 7-day programmable thermostats continues that tradition, providing the convenience of pre-set temperatures for every day of the week.

The Honeywell RTH7500D Conventional 7-Day Programmable Thermostat was designed specifically for homeowners who prefer push button controls, rather than touch screen technology. The model is also priced slightly lower than its touch screen counterparts. All of Honeywell’s 7-day models allow users to program four settings for every day of the week, with terminology – wake, leave, return and sleep – that guide you through the process.

(Click here to download the users manual for the RTH7500D)

Installation – Pros and Cons

Honeywell thermostats can be used with a variety of heating and cooling systems, but some consumer reviews cited trouble in determining the wiring configuration with atypical installations. The product comes with stickers to help identify which wire goes where. Programming the thermostat is fairly easy, and the manual guides you through any confusion in terminology.

The RTH7500D model has an “automatic” option that allows you to set a single temperature that the system will then maintain, switching from cooling to heating systems as needed. It’s a handy option when you’re home all day, and it can be toggled off when you’re not.

User-Friendly Button Interface

Many homeowners will find the button interfaces more user-friendly than those with touch screens. The buttons ensure you won’t accidentally hit the wrong setting. To conserve the batteries, the display remains in “dim” mode until a button is pressed, which triggers the backlight.

The display itself is clear and concise, showing the current temperature, your pre-set temperature, the current time and three options for turning on the fan, setting the clock and for bringing up the scheduling menu. Up/down push buttons to the side make adjusting the temperature simple, even in the dark.

>>> For more details price reviews and ratings about  Honeywell RTH7500D Click here … <<<



Most standard brands available today are Rheem, Trane, American Standard, Carrier, Bryant, Lennox, York, Amana and Goodman. Other Brands such as Maytag, Frigidaire and Tappan which are manufactured by Nordyne. Non standard brands such as Florida Heat Pump (FHP), First Company and Mitsubishi.


It is very important that you purchase the correct size system for your home regardless of the size you currently have. What I mean by that is, don’t just replace with the same thing you have now. It could be mis-sized and causing you problems that you are not aware of such as short cycling (causing humidity problems) or over working (shortening its life span).

Today’s systems are different in design then your older system. In order to achieve the higher efficiencies, they have installed a TXV valve which regulates the flow of the refrigerant. These keep the units from working inefficiently but do not allow for deficiencies in sizing.

The best way to properly size your new system is to have your contractor do a Heat Load Calculation also known as a Manual J. If not, as a general rule of thumb, 500 sq. ft. per ton of a/c living space for a single family home (example 2000 sq. ft. of a/c living space is a safe bet at 4 tons) . Factors may vary depending on exposure of home, how many windows and type, attached or free standing home, single story or 2, inadequate insulation in attic and leaking ductwork.

Your contractor should also check your ductwork in the attic to make sure it’s sized properly for the new system. Don’t assume or let him tell you it’s fine if he hasn’t looked (red flag).

Seer Rating:

Acronym for Seasonal Energy Efficiency Rating. The higher the SEER rating the lower your electric bill. Some utility companies offer rebates based on the SEER rating. 13 SEER is the minimum rating allowed by law and can go up to 21 SEER or higher depending on the brand. Keep in mind that the higher the SEER the more costly the equipment. For a single stage unit 16 seer is about the highest and probably the most popular now because of price.

Types of Central a/c systems:

Split systems, package units and water source heat pumps (less common and usually in high rise condos). A split system has 2 units, a condenser outside and an air handler inside. A package unit has both in 1 on the outside. A water cooled unit has both inside and is connected to a water source.

Single Stage vs. 2 Stage:

Single stage system is the least expensive and the more common system. It uses one compressor in the outside unit (condenser). A 2 stage system has either 1 compressor that changes speeds or 2 compressors that change back and forth according to demand. A 2 stage unit also has a variable speed air handler. The benefit to the 2 stage system is better humidity control, better air circulation and quieter operation.This system will keep your home feeling more comfortable over the course of a day because it adjusts to the changing environment of your home. Factors such as outside temperature, direction of the sun as it relates to your home and humidity will be compensated by this system.Also check your old thermostat.You might have to replace it and get a new one preferably programmable type that support your system.

Types of Heating:

Heat strip, heat pump, gas furnace. A heat strip is a coil in the air handler that heats up like a toaster. The air blows over it as it goes through the air handler. A heat pump uses a reverse cycle on the compressor to produce heat and can be supplemented with a heat strip for additional heating (used in cooler climates). A gas furnace gets its heat from natural gas and is used in colder climates.

Refrigerant Line Sizing:

These are the the copper pipes that carry the refrigerant (or freon) back and forth from the condenser to the air handler. There are 2 lines. A liquid line and a suction line. They must be the correct size according to the manufacturers specifications. Make sure that your contractor checks them to see if you have the right size for the new unit. Don’t assume they are correct even if you are replacing with the same size a/c. They may never have been correct. Under sized lines cause premature failure of the equipment due to low lubrication of the compressor and will lower the SEER rating that you are paying for. If a contractor does not check these (red flag).

Rule of thumb.

1.5 to 2.5 tons minimum size is 5/8 and 1/4 up to a 50′ run.

3 to 3.5 tons minimum size is 3/4 and 3/8

4 to 5 tons minimum size 7/8 and 3/8

Electrical Specifications:

Electrical wiring also needs to be sized properly. Don’t assume because you lived in your home for 20 years and your a/c has worked fine and you’ve never had a fire that it’s ok. Breakers also need to be sized properly. Again, don’t assume that what you have is right or safe. Make sure your contractor checks this without you asking. if not (red flag). Rule of thumb for air handlers

up to 30 amp breaker #10 wire and you can use a 5 kw heater

up to 45 amp breaker #8 wire and you can use a 8 kw heater

up to 60 amp breaker #6 wire and you can use a 10 kw heater

Rule of thumb for condensers

Varies by size and brand but wire sizes and breakers listed above are the same.

Manufacturers, Utilities and Government Rebates:

Manufacturers have rebates usually in the spring and the fall. The higher the price of the equipment, the higher the rebates (typically up to $1200). Keep in mind that the dealer absorbs half the cost of the rebate, so it gets built into the price to the consumer. Here is a link for state, local and/or utility incentives in your area http://www.dsireusa.org/. Power utilities may also have rebates for repairing ductwork and replacing insulation in the attic. Federal Energy tax credits ended on December 31, 2011 but legislation is in congress for new tax credits.

Hiring a Contractor:

Your local power utility company may have a list of participating contractors for any utility rebates. Better Business Bureau is good if you take the time and check how many complaints a particular contractor has (too many and red flag). Angie’s list is also good. The best way to find a contractor is by word of mouth. Ask your neighbors, friends and co-workers. If they’ve had a good experience, they will surely let you know, if not then you know which contractors to stay away from. Get 3 estimates. If you do your research and call reputable contractors, then 3 should be enough. Too many will definitely get you confused. Make sure that they leave you a written estimate with all work to be done as well as model numbers and prices. If all these things are not on the proposal or if they tell you that they don’t pull permits for the job then beware. Most cities require permits even if your replacing with the same thing. This is to make sure that your contractor did all the work according to code and that your home is safe.

Beating the Puzzle of Thermostat Wiring

Things You Should Know About Thermostat Wiring

Thermostat Wiring is a method of installing the thermo regulator in your house, office, car, or where else possible. It may be installed by yourself or by an electrician as you wish. Meanwhile, upon installation, the thermostat’s role is to primarily control the temperature by using its simple user interface with the internal workings of your home as well as its adjustable set point. It is used to regulate the desired temperature in a place. These are commonly used in no tropical places in America and in Southeast Asia to in order to ease the discomfort with the weather or climate. Usually, when the desired temperature is achieved, the systems get to be turned off while the expected temperature is delighted in.

Thermostat Wiring

Red C-24 V supply line from air conditioner transformer.

Red H-24 V supply line from Heat pump transformer.

White-To heat pump relay.

Yellow-To air conditioner relay.

Thermostat Wire
Color Codes

Source : dr-fix-it.com/ttt/10005.html

Rh Red 24 Volt Hot for Heating
Rc Red 24 Volt Hot for Cooling
Y1 Yellow First Stage Cooling
Y2 Blue Second Stage Cooling
G Green
Gray *
Energizes Indoor Fan
W1 White Energizes First Stage Heat
W2 Black Energizes Second Stage Heat
O Orange Heat Pump
Reversing Valve
Energized In Cooling
B Brown Heat Pump
Reversing Valve
Energized In Heating
C Brown** 24 Volt Neutral
(Common) leg

*     Found in some Carrier furnaces
**    The brown is often the first choice to use for the 24 volt common leg but white, black and blue are also used.


All of this goes out the window if the person before you didn’t know or care to use the accepted color codes. Sometimes it is simpler to take down the existing wiring and re-terminate using the accepted color codes than it would be to map a “creative” wiring scheme.

The most basic of systems only need 2 wiring for control. They bond to a 2-string thermoregulator. The terminals in the label that are commonly ‘R’ and ‘W’ usually work at 24V. The source of this control electric power results from a control electrical device fitted probably just away from, or through the chamber body. The line voltage feeding the heater is turned down to reliable level of 24 volts. Then, after making a series of loops through at least one safety device, the power goes up to the Thermostat Wirings. In exchange with the room temperature reaching the desirable set point, it triggers the contacts to close. Thus, completing the circuit to the gas valve allowing it to open, the main burner to ignite, and begin the cycle of heat production by the thermostat.

There are also some common types of thermostat wirings where you can be able to find 3 or more wirings. I commonly has terminal with the 3 wirings ‘R’, ‘W’, and ‘Y’. This model, when selected for cooling and when it reaches the point above the set-point, the thermostat will close the connection between the ‘R’ and the ‘Y’ terminal. This initial process shall trigger the wholeness of the machine to start the cooling process. This provides the cooling for the evaporator coils built in the machine.

For further reading you can see this  http://thermostatonline.com/ritetemp_Professionalreferenceguide.html

The Continuing Cycle

When the cycle starts, the temperature of the heat exchanger arises as the fan blower motor starts moving air through the heat exchanger and takes out the heat through the ducting in your home. If, for any reason, the fan fails to run, it will be normal but dangerous for the heat exchanger to get too hot. This triggers the hi-limit temperature device to open to the gas valve, closing the valve and stopping the heating cycle.

Through time, climate control systems have evolved considering that the demands from our generation have vastly arouse. Today, thermostat units are more efficient, and have more features to boast about. No wonder, that the use of the old Thermostat Wiring technology have been long forgotten by most. Meanwhile, some people still are fond of using the old technology, this is good when the technology works real good for them but in some cases of unnecessary damages or malfunction of the machine, the pieces that need to be replaced are most often unavailable in hardware stores, that may lead for them to get to either purchase another old model or adapt with the machine that the new tech has to offer.

Thermostat Settings

  • Set the air conditioner’s thermostat not lower than 78°F during summer months.

  • By winter, set it to 68°F. This will help you minimize energy costs or expenses.

  • When adjusting the temperature on the thermostat, do it gradually to ensure that every family member is comfortable with the adjustments, especially if you have toddlers or babies at home. You can do this by adding or reducing the temperature a degree at a time in a week.

Honeywell RTH7600D Review


Many homeowners grew up seeing the Honeywell name on their household thermostats. The brand is so deeply imbedded in popular culture that their model known as “The Round” is displayed at the Smithsonian as an iconic American product.

With that kind of legacy, consumers expect a lot from a Honeywell thermostat, and the RTH7600D Touchscreen Thermostat delivers.

The RTH7600D model is compatible with a variety of heating and cooling systems, including heat pump systems. Configuring the thermostat to alternate systems requires using its advanced programming options.

(Click here to download the users manual for the RTH7600D)

Simple, Set and Forget Features

Set the thermostat at the temperature you want, and this thermostat ensures it stays there, automatically swapping between heating and cooling. Its digital display is easy to read, easy to understand and easy to program.

Some consumer reviews complained that the advanced programming interface uses numbered codes like “0300” instead of plain text. The manual clearly explains the codes, so this may be a minor irritation.

Advanced programming also allows users to set reminders to replace the filter and batteries, features that reviewers liked.

Don’t expect the RTH7600D model to serve as a night light. The backlit display stays lit for about eight seconds, then goes dark to conserve the batteries.When lit, the display is extremely user-friendly.

Clear up/down arrows allow you to easily adjust your pre-set temperature, and the system holds the new setting.

Care-Free Programming

This Honeywell thermostat has all the programming options you’d expect from a quality 7-day system, allowing you to easily program the system for variable settings for each day of the week.

The feature that really sets this model apart is its “recovery” option.

Keep the system turned off while you’re a work, set the time you want it to recover your optimum temperature, and the system ensures that your home reaches that temperature by the time you walk in the door.

>>> Click here to more details price reviews and ratings of Honeywell RTH7600D … <<<

Lux TX9100U Review

This thermostat is compatible alongside pretty much any kind of heating or cooling system available on the U.S market.

The Lux TX9100U showcases a user-friendly energy-saving design that is easy to learn even for the not so tech savvy people out there.

Due to the fact it’s programmable the TX9100U utilizes energy only when it’s necessary this unit will be a tremendous factor in helping you to spare money on your energy bills as well as protect the environment.

For safety and further benefits this advice is completely free from mercury.

Because of the large backlit display patented Lux Speed Dial as well as pre-programmed energy-saving plan the TX9100U is extremely simple to use.

The TX9100U allows you develop an entirely different program for every single day of the week and you are able to submit four different time intervals and temperature settings in a 24-hour period.

Whenever you are planning to leave your home for a longer period of time it’s possible to use the vacation hold feature to make sure that you are not paying to heat or cool an empty house.

Save Money and The Environment

Like all programmable thermostats the TX9100U helps reduce energy consumption but this efficient devicetakes savings a step further.

To maximize your home’s energy efficiency the TX9100U comes preprogrammed with a default heating and cooling schedule that’s designed to save up to $500 in energy costs over a year.

>>Click here to find more detals price reviews and ratings of Lux TX9100U…

Lux TX1500E-010 Review

The Lux TX1500E is a great choice for people with little or no experience in replacing their old thermometer with a new one.

The only thing you need to focus extra on is marking your old wires so you know where to connect them on the new thermometer.

Installation Made Easy

The easy and fast installation and its ability to keep a nice steady temperature makes this unit a global favorite with home owners.

The ability to pre-program the AC/Heat to switch on and off at certain times during the week is a feature that many thermostats can’t handle all that well. But the Lux TX1500E handles this smoothly all the time, it truly is a “set-and-forget” feature that should be standard with every digital thermostat nowadays.

You can program the heat to switch off when you are at work and to automatically switch it back on when you come back home. This is crucial in keeping your heating bill as low as possible.

Issues With the Screen

The blue blacklight screen on this device is very easy to read and lights up when a button is pushed.
Some customers have expressed a mild irritation with having to push a button to view the current setting or the target temperature.

This thermostat is a top rated product by Consumer reports and is extremely affordable compared to other similar thermostats on the market.

>>Click here to find more detals price reviews and ratings of Lux TX1500E…

Honeywell RTH230B Review


As the leading manufacturer of thermostats, Honeywell offers more than two dozen programmable models. The Honeywell RTH230B is one their most affordable, offering precise temperature control whether the family is at home or away.

With a simple, basic operational system, the RTH230B allows users to save up to 33 percent on their energy bills, without having to tackle complicated programming.

The model doesn’t have every bell and whistle offered in high-end models, but has more features than one might expect for the inexpensive price. The RTH230B works for central gasoil or electric furnace systems.

Easy Programming + Consumer Reactions

The Honeywell RTH230B can be pre-set to program four time periods of the day, or “zones,” for both weekdays and weekends. A “house” icon displays when the system is running on auto-mode. Users can simply press the Mode button until the icon disappears to run the unit manually.

(Click here to download the users manual for the RTH230B)

The RTH230B also lets users interrupt the auto-mode by pressing the up/down temperature control buttons, a feature that consumer reviewers particularly liked. After two hours, the system shifts back to auto-mode. Not having to toggle through controls to adjust the temperature was a big plus for many reviewers.

Lack of Back-Lit Display and Hinged Cover

While some consumer reviews complained that the unit does not include a back-lit display, the screen does feature clear, easy-to-read time and temperature read-outs. The unit lacks a hinged cover, which bothered some reviewers as well. The RTH230B covers snaps on and off.

For the most part, reviewers reported easy installation, with many reporting that the unit was installed, programmed and operating within minutes.

The model has the accuracy that consumers expect from a Honeywell product, keeping the temperature to programmed settings to within a single degree Fahrenheit. While Honeywell offers programmable thermostatswith more extensive options, for those who prefer simple controls and ease-of-use, the Honeywell RTH230B Programmable Thermostat is a good option.

>>> Click here to more details reviews price and ratings about Honeywell RTH230B… <<<

Honeywell RTH8500D Review


If you are looking for a thermostat with touchscreen function that doesn’t use batteries then you will most definitely come to love the Honeywell RTH8500D.

(Note: It is able to run on batteries if your system does not provide 24vac power.)

This unit is equipped with every feature that you can ask for in a programmable thermostat.

The installation is really easy if you are reading the manual carefully and the thermostat itself looks great when mounted on your wall.

(Click here to download the users manual for the Honeywell RTH8500D)

The unit will automatically switch between the temperature range settings “heat” and “cool” meaning it’s not a hassle to set the perfect temperature range. Although, this function is disabled by default so you have to look in to the advanced options on the screen to enable this feature.

You are able to program each of the 7 days of the week individually with up to 4 different events (wake, leave, return, sleep).

Does What Cheaper Thermostats Can’t

One of the most intelligent features of this unit is the “recovery” mode which means that it learns how long it will take to either heat or cool your living space and it simply turns on the heater or air conditioner early so that it will reach the preffered temperature at the time you have selected.

The cheaper thermostats have a tendency to only turn on at the set time and the the temperature catches up to the program.
The RTH8500D always anticipates you needs, meaning if you want it to be 73 degrees when waking up at 8:00 then simply set the wake-up event to 73 degrees at 8:00. This thermostat takes care of the rest.

>>> Click here to find the best price on the Honeywell RTH85000D – Online … <<<