Honeywell Wifi Smart Thermostat (RTH9580WF) Review

Published by on 25th May 2014

Honeywell Wifi Smart Thermostat

The Honeywell Wifi Smart Thermostat (RTH9580WF) is Honeywell’s response to the Nest Learning Thermostat.  A wifi smart thermostat that gives you control from anywhere in the world via the internet and one that can even learn your personal preferences over time. Does any of this sound familiar to you? Honeywell definitely thought so and are still in litigation with the Nest over violation of existing patents…but that is definitely not a story for here!

When most people think of a Thermostat, the first name to come to mind is usually Honeywell.  This is not really surprising given that their history spans back well over 125 years. Seriously, they have been in the thermostat business for that long.

I am sure you can appreciate; thermostats have come a long way since that first patent in 1885. The Honeywell wifi smart thermostat is no exception. It brings to the table the control, dependability and quality that has become synonymous with the Honeywell name, as you will see from this review.


product-detail-smart-greenThe Honeywell Wifi Smart Thermostat (RTH9580WF) has been purposely designed for the average home DIYer installation. Other than a screwdriver and a spirit level there should be no other tools required. The wire ports are simple push in clips, although using a pen to open the ports can be helpful during wiring. So the only thing you have to worry about is correctly getting your wires connected. Simple, right?

Actually, it’s not quite that simple. There seems to be one glaring omission from a lot of the information on-line. In fact, during my research, the first time I actually came across it was when I was reading the instruction manual. Yes I do read them! In this case it was a good thing as the proverbial horse had definitely bolted before I could shut the gate.

What is this glaring omission?

[Drum roll]…It requires a common or ‘c-wire’ in order to work. At this point you may be thinking, what’s the big deal? My heating/ cooling system has a c-wire! Well it turns out that the c-wire is not actually all that common!

The Honeywell wifi smart Thermostat needs to draw power from the system in order to operate. There is no backup power, no batteries, no power sharing. It needs to be connected to a source of 24v power otherwise it becomes a completely useless wall mounted ornament…and more importantly you will not be able to heat or cool your home.

So how can you tell if the thermostat is compatible with your system? Well as a very rough guess and a starting point consider these factors or indicators. Does your current thermostat have a big, back lit screen? If yes, then it has to be drawing power from somewhere, the most likely place will be by using a c-wire.

Was your heating/ cooling system installed in the last 5 years or so? If yes, the chances are high that you have a c-wire. It turns out that over the past 10 years and more pronounced over the last 5 years, C-wires have become a common element to most system installs. If you have a newer system the more likely you are to find the thermostat to be compatible with your system.

But I wish it were just that simple to tell. These 2 factors only give you a quick indication, without having to get your hands dirty, to the compatibility with your system. When you start getting into the detail of the thermostat you find that there are other factors that need to be considered.

The upside is Honeywell have done a good job of posing some questions to help you get through these factors. They also provide alternative options to try and ensure the thermostat will be compatible with your system.

The downside is that unless you thoroughly research the thermostat before you buy you won’t know 100% if it is going to work. To me this issue may as well be placed in some small print, hidden in the last full stop of the page, only to be found by a trained spy.

(You can check the brief product details over at Amazon for the Honeywell Wi-fi Smart Thermostat).

It’s not that I think Honeywell are trying to hide anything or mislead us. In fact as the questions exist it shows they have thought about it. It’s just that they have possibly overlooked that not all of us have a working spymaster 3000 to hand in order to find these questions.

Luckily I always keep mine handy so can summarise the questions here for you. In order to answer these you are going to have to do some detective work yourself and look at your thermostats wall plate.

Let’s start. Does your current Thermostat have:

  • 110v or higher written on it?

  • Thick wires that are connected using wire nuts?

If you answered yes to either of these or even both, then you have a high voltage system and the thermostat is not compatible. Sorry, in all likelihood you are going to need the services of a trained professional if you want to update your system. If you answered no to both then we can move on.

  • Is there a wire connected to the c terminal?overlay-wiring-3-image

(Duh!) If this is the case then you have a c-wire and thermostat should be compatible with your system.

  • Is there an extra wire that isn’t connected to any terminal?

Ok, this one may sound strange but quite often when the original thermostat wiring was installed a spare wire was left available. Sometimes it is obvious as you see it as soon as you look at the wall plate wiring. Other times you will find it tucked back in the wall, wrapped around the cabling. Either way, connect the other end to your systems c terminal at the furnace and hey presto, instant c-wire. No extra cost for a c-wire installation.

  • Is there a wire connected to the g-wire?

On gas, oil or propane forced air furnaces the g wire is used to allow manual control of the fan. What you can do instead is disconnect this terminal and reassign it to the c-wire at both the furnace and thermostat. Again, you have an instant c-wire.

But, does that mean the fan isn’t going to work? Well no, the fan will still work fine but only the furnace will be able to use the fan. What you lose is any manual control of the fan. To some of us this may not be a big deal but others may disagree with this loss of manual control. Hey, don’t shoot the messenger; I am just explaining the options available to you.

Another important point for consideration, if you do decide to go down this way of reassigning your g-wire, is the building code in your area. Making this kind of wiring change may go against the building code so make sure you check first.

Now if you don’t have the c wire, or a spare wire or a g-wire, it may not all be doom and gloom. Especially, if you have your heart set on one of these thermostats. There are 2 other possible options for you to consider.

My top option is to get a c-wire installed. Yes, this is additional cost but this is becoming more and more a staple for all new thermostats. Over the long term you are in all likelihood going to have to get one at some point. Why not just bite the bullet now? In doing so you are future proofing your system…and your ultimate smart home.

My second option is more for information rather than a suggestion or recommendation. So why mention it? Across the internet there are many examples of people using this method so if I don’t let you know about it you may feel I haven’t been totally open or honest with you. So with that said, and with a little caution, here goes.

You could install a separate 24v power cord. Now, I am not going into how you could use this method for 2 main reasons.

Reason 1:      By introducing an independent power source you may inadvertently void your warranty. More importantly, if something was to happen, that causes damage or a fire (I did say if) how would insurance companies view this? Ok, I may be being paranoid here or ultra conservative but I am guessing they may view this as tampering and so accredit blame to you for the ‘incident’.

Reason 2:      This one is a bit more cosmetic nature. You will need a power outlet nearby to plug in the power cord. No big deal? What about the wire now trailing down your wall to the outlet? Personally, I would hate this and would never hear the end of it from my significant other.

Now that is out of the way and you have now chosen a way to power your thermostat it’s time to install. Once past the wiring options for power, the rest of the install is pretty straight forward. Especially if you follow these 4 very important tips.

TIP#1Make sure you turn off the power to the thermostat before you do anything. You don’t want to get a shock when doing the install.
TIP#2Don’t let the individual wires touch. This may cause a short in the circuit that could result in a very expensive repair job with your HVAC system.
TIP#3In the box for the thermostat there are wire label stickers. Use them. It’s a good idea to tag the wires to help you remember their designations as the wire colors are not always kept standard. (Surprisingly there is no code for this!)
TIP#4Before you start, take a photo of the wiring. This will give you a reference of how the wiring was before you started. This can be invaluable if you have to reinstall the old thermostat or if you have problems that you later have to talk to support to resolve.

Follow these tips and the rest of the install should be a breeze. With the wiring of the wall plate photographed, wires tagged and powered off, all you have to do is:

  • Remove the wires from the old terminals. (Don’t let them touch)

  • Remove the old wall plate

  • Install the new wall plate, using a spirit level to make sure the thermostat will be straight. (A crooked thermostat would drive me mad!)

  • Simply, push wires into the corresponding terminals. (Use a pen to help if you have difficulty)

  • Clip on the thermostat faceplate and turn on the power.

Honeywell wifi smart thermostat install…DONE.


product-detail-smart-goldSo as the thermostat starts to power up, the next step is the setup. The initial set up is also quite straight forward. It’s all done through the thermostat touch screen. The thermostat poses a few questions and you answer them. If you get stuck or need more information, there is a help button that gives more details.

After choosing your preferred language the next option is to decide if it is for home or business use. The reason for this question is to change the terminology the thermostat uses and differences in preset scheduling. Essentially, all this does is refer to rooms, not offices and uses sleep times and wake up times rather than occupied hours and unoccupied hours. That sort of thing.

You then get to name your thermostat. Why? The default name may be OK if you are only running 1 thermostat. If you have a number of them, say for multi-zones, then you will want each to be uniquely named so you can identify them and know what area you are controlling.

The next step is to indicate if your system is used for heating, cooling or a combination of both. Then the type of system you have, be it a forced air, Heat pump or hot water/ steam system. The screens following this decision further detail the specifics of your system to ensure you have it set up appropriately. Do you have 1 or 2 heating levels? How many cooling levels? Nothing too difficult.

At this point the Thermostat is working and already controlling your system to the built in presets. With the initial set up complete you will be asked if you want to connect to your wifi network. The Thermostat doesn’t actually need a wifi connection to control your system so you could opt to do it later but why come this far only to stop now!

As with most Wifi enabled thermostats, the Honeywell wifi smart Thermostat uses a wifi connection to allow remote control of the thermostat and to provide automatic system updates, if required. If your Wifi connection goes down, no worries, you will still be able to control your heating/ cooling needs directly from the thermostat. It supports all common network security protocols too, so no weak spot in your home network.

Overall the draw on your home network will be minimal so you and your family should not experience any slow down or bandwidth issues. To connect to your wifi network is just a matter of selecting your network and then input your password. This is all done using the on screen keyboard so again all very simple.

The thermostat will establish a connection and then provide the MAC address and CRC you will need to be able to gain remote access. At this point you have 3 options. Leave them on screen until you register your online account, take a photo of them for reference or check them against the ones supplied in the box on the thermostat ID card (and on the back of the thermostat but you are not going to want to take it off now, right!). 99.9999% of the time they will be the same but it never hurts to check.


Why do you need the MAC address and CRC and why are they important? The MAC address has nothing to do with apple, in fact MAC stands for Media Access Control. This is a unique code that allows the thermostat to connect and talk to your network. Everything that connects to a network has one. Without it there would be very little going on. Kinda like a postman (or postwoman) knowing your name but not knowing where you lived. The MAC address solves this.

The CRC or Cyclic Redundancy Check is an error detecting code. Without going into the detail too much, think of it as preventing any electronic Chinese whispers from occurring. It makes sure whatever the message sent, it gets transmitted correctly. As an example, imagine driving home in your car and telling your thermostat to warm up 10°. You get home and find it actually cooled your home 10°. This is what the CRC prevents.

To be able to get remote access you need to register your thermostat. To do this you need to set up an account with my total connect comfort service. This is Honeywell’s tried and tested portal to controlling your Honeywell products not just this thermostat. Once you have an account and verified it, you need to enter the MAC address and CRC. Now you are ready for world dominat…no wait, sorry, wrong product…make the most of your new thermostat.


product-detail-smart-pinkNow we get to the meat in the sandwich for any thermostat. The reason for a programmable thermostats existence. Its divine purpose. The cog in your ultimate smart home wheel. Scheduling.

Why am I making such a big deal about it? Well research has shown that in all homes that contain a programmable thermostat, 90% are NOT actually programmed with a schedule. The owners still manually change heating and cooling as and when needed. They are just not making the best use of the equipment.

With heating and cooling contributing to around half of your energy bill, this means that this is a missed opportunity. With the appropriate program not only will you be able to reduce your energy usage but also make some substantial savings and coincidentally protect the environment.

The Honeywell wifi smart Thermostat comes with a preset program. So even if you don’t normally program your thermostat you are already covered. Honeywell has just moved you into the 10% of the population. If you were to do nothing more with the thermostat you should start to see some benefits straight away.

The chances are that these are not going to be optimised settings reflecting your personal preferences. But it is a start. Let’s face it, if you are reading this review then you will probably be looking to set your own program, anyway. So what can this thermostat do?

This thermostat is a 7 day programmable thermostat. What does that mean? You have complete control and flexibility of your program every single day. You can have a program that remains the same on each day of the week. Or you can have a program that changes on every day.

For the majority of us, it will fall between these 2 extremes. We will have one program for the working week and another for the weekends so that we can enjoy those sleep in’s! Whatever your preference the thermostat can handle it.

With regard to presets, there are 2 types of preset depending on whether you chose the Business or Home setting. Other than terminology there is no real difference between these except for the number of periods, or on/ off cycles, in the day. The home setting has 4 defined on and off periods by default whilst the business setting only has 2 by default.

These can be changed in the settings and have the same features so in essence they can be considered as the same. For that reason the rest of the review will only refer to the Home setting. Just be aware that anything mentioned will also be available in the business setup.

How do these periods work? To best explain this let’s consider a general working day as an example. Normally on a work day we get out of bed at 6am. After breakfast we get ready for work and leave the house at 7:30am. After work, we arrive home at 5:30pm and settle in for the evening. At 10pm we go to bed.

In this case we would need 4 periods. The schedule we may have could look like this:

Period 1Wake6:00 am70°
Period 2Leave7:30 am62°
Period 3Return5:30 pm70°
Period 4Sleep10:00 pm62°

At the weekend, we may stay home, so we wouldn’t need so many periods, maybe just 2 periods are needed. For that reason our weekend schedule could look like this:

Period 1Wake8:00 am70°
Period 2Sleep11:30 pm62°

Ok, these are just brief examples to demonstrate what can be done. But you should get the idea. So how do we program these differences and what can we program?

In the menu system of the thermostat and on the remote app there is an option to create/ edit schedule. In here you will get 3 options:schedule

  1. View/ edit – This allows you to view the current schedule and make any adjustments or tweaks you like without going through a full schedule program.

  2. Guide Me – This builds a new schedule based on questions the Thermostat will ask you. These will range from what time do you wake up? To what temperature do you want when you are away? At the end of the questions you would have built your own custom schedule.

  3. I’ll do it myself – Gives you full access to modify and create your own personal schedule.

The ‘I’ll do it myself’ option may seem a little overwhelming but it really is straight forward. Start by choosing an individual day(s), all weekdays or weekends. Then the particular time period for those days, being wake, leave, return or sleep. The only thing left is to choose the time and the set temperature you want to heat and cool. That’s it. That’s all you have to do for that time period. Just rinse and repeat for all the other periods.

Ok maybe not just that…but that’s it for the basic setup. Another thing you can do is to delete the period if you don’t need it. There is also an advanced option to adjust the systems fan if you are using a forced air system. This allows you to have it on all the time, to circulate air or if you leave it on automatic it will only be used when heating or cooling. This is a nice feature that most other thermostats normally overlook.

What about the times you want to change the temperature instead of sticking to the schedule? Are you tied down to the schedule? Nope, you still have the ability to override the schedule. Either through the app or on the screen you can select a new temperature. You can also select a ‘Hold Until Time’. The thermostat will hold that new temperature and override the schedule until the set time. Alternatively you could make it a permanent hold until you cancel it.

There is also a vacation mode that you can use when you go away. This prevents the system from sticking to your schedule whilst you are not there. Honestly, do you really want your system to heat your house or cool it, whilst you are not there? Not only will it waste energy but it will also cost you a fair bit too.

An important factor to consider for all your scheduling is the away temperature you set. Why? This is where you make your energy savings and directly running costs. Essentially, in winter you don’t want your heating working all the time and in summer, cooling non-stop. But that’s exactly what happens if you don’t set an away temperature.

Ideally, you want these temperatures to go as low or as high as you can. But you need to ensure that they are still appropriate. Why? If the temperature goes too low or too high this could have a huge impact to your pets, the plants in your home and could have a detrimental effect on your home (think frozen pipes in winter). It becomes a balancing act between comfort and cost.

With the schedule programmed and an appropriate away temperature set you should start to see your energy savings start to roll in. That’s the good news. Well OK, not all the good news. By purchasing the thermostat you could be entitled to a rebate. Yes you heard right.

The bad news is that Honeywell don’t actually provide any type of reporting regarding energy usage. This is a disappointing omission by Honeywell in my opinion. I like to see the data so that I can tweak to get the best settings. But you may not see that as being as important to you.

In truth, this is probably a nice to have feature rather than a must. The result remains the same, energy saving and cost savings you will see on your bill. But it would have been nice to see it in real time.


Honeywell-WiFi-Smart-Thermostat-InterfaceLet’s start by looking at the overall look and build quality of the thermostat. Here it seems is one of the more contentious aspects of the thermostat. A common complaint that I came across during my research was that a lot of people were disappointed by the overall build quality.

I can already hear you asking why? What’s wrong with the thermostat? Actually nothing, there isn’t anything wrong. To me, it all comes down to perspective.

Most digital thermostats on the market tend to be made from white plastic and have a contrast display. When they are on the wall, they stand out but as we have got used to them we accept their looks. The display is small, functional and tells us what we need to know. All very standard.

The Honeywell wifi smart thermostat, breaks this standard mould. Gone is the white plastic and small screen. Instead we have a small full color touch screen monitor. The edging is a silver colored plastic but this just fits the monitor look. All in all, the thermostat is well made and a distinct step up from the standard.

So why are some people “disappointed”? They are comparing this to the Nest. The solid stainless steel, minimalist, apple-esque look. True, they are quite comparable thermostats feature wise. The problem is the Nest team have skewed some people’s expectations. Realistically, both thermostats have moved on a fair way, just with different focuses. Remember, whilst the nest looks good, it doesn’t have touch screen technology.

And that’s where the Honeywell wifi smart thermostat comes into its own. The color touch screen makes the ease of use and information at your fingertips so simple and more importantly intuitive. The home screen itself is a wealth of information. It displays:

  • Current indoor temperature and humidity.

  • Current schedule status.

  • Ability to change the temperature. This leads on to options to select it as a temporary or permanent hold period.

  • Current system status (heat or cool)

  • Outdoor temperature and humidity (if you are connected to wifi)

  • Current date and time (automatically updated when connected to wifi)

Across the top of the home screen are the different menu options, Home, Fan, System and Menu. The fan mode options allow you to select to turn the fan on, Automatic, circulate and follow schedule.

smart-product-detail-feature6-image2On leaves the fan on all the time allowing you to push air through the system all the time. Automatic only uses the fan when the system is actively heating or cooling. Circulate randomly turns the fan on (about 35% of the time) to, well, circulate the air in your home (no one like’s stale air or those residual cooking smells). And follow schedule…follows the set schedule.

The systems tab gives the options for what the thermostat controls in your home system. Heat tells the thermostat to only control the heating system. Conversely, Cool, only the cooling system. Off, I think speaks for its self. In this mode the thermostat is just monitoring temperature and humidity in your home.

The next 2 options only appear depending on the type of system you are running. Automatic is for systems that are both heating and cooling. This option gives the thermostat the ability to select either heating or cooling depending on the need. It means you don’t have to tell it to change from heating to cooling, or vice versa. It just does it.

The emergency heat option is available if you have a heat pump installed. All heat pumps have an emergency or auxiliary heat setting. The purpose of the setting is that if the heat pump breaks down, the unit can still heat until the heat pump can be fixed.

Sometimes this is described as a type of heating boost for when the weather is very cold. This is actually untrue; it has nothing to do with extra heating capacity. Switching to this mode is a backup option only as running Emergency Heat will decrease your efficiency, increasing your energy usage and costs.

The final tab is Menu. Under this tab you find all the scheduling options to create, view and edit. There is also the vacation mode, as we have previously discussed, along with the ability to view the equipment status.

Color themes allow you to change the display background (more on this later) to whatever you want. Clean screen locks the screen for 30 seconds so that you can get rid of those annoying finger marks. This is indispensable in my home where the kid’s sticky fingers seem to find their way onto all my gadgets!

Speaking of sticky fingers, the security settings helps prevent any unwanted changes. There are 3 options here. Unlocked gives full access to the touchscreen. Partially locked only allows the temperature to be modified. Fully locked prevents any access…a must in my home! You are able to enter a 4 digit password to give extra assurance that things don’t change without your say so.

Preferences lets you customize how the thermostat acts and controls your system From simple things like setting when the backlight turns off or dims, restoring factory defaults through to the more advanced display offsets and number of scheduled periods.

If you want to make changes to your system in the future, system setup can be used. This runs you through the initial set up again…just in case you forgot something, don’t like how the system is working or made a mistake during installation.


smart-product-detail-feature9-imageSo what kind of systems can be controlled by the thermostat? As we have already mentioned, it works with most common 24v systems. This means it will control forced air, hydronic (hot water/ steam), electric, gas/ oil and propane systems. It’s also able to manage heat pumps too or combinations of these systems. So most home systems are covered.

The only true, possible limitation is the number of stages it can control. It’s only able to control up to 2 stages of heat and 2 stages of cooling. OK, not really a limitation but I couldn’t make it all sound good, could I! It’s also able to be used to control zonal heating or cooling. In order to do this you will need a separate thermostat for each zone.

At the heart of this control is the renowned Honeywell temperature sensor. These are so good that Honeywell state that they are accurate to ± 1°. This is a big claim taken that other competitors can often struggle to meet ± 3°. There is also an onboard humidity sensor too but this is only used to monitor the indoor humidity.

But it’s this temperature sensor that gets the most praise online. During my research a common statement seen over and over again is how good the sensor is. It uses this accuracy to control the temperature in the home to the same ± 1°specification. This means that the temperature swing is incredibly small.

What is temperature swing and why is it important? Temperature swing is the range that the thermostat will control the temperature between. As an example, if you set your temperature to a single temperature say 70°. The thermostat will control the temperature between 69° and 71°. When it drops below 69° it will initiate a heat cycle. If it exceeds 71° then it will initiate a cool cycle.

A problem that all thermostats suffer from is latent or residual heat. What do I mean by this? Well, when a thermostat heats (or cools) it sends a signal to the system. The system turns on and delivers heat. It keeps on delivering more and more heat or energy until the thermostat says it has reached the desired temperature.

The problem is that it still delivers heat for a time afterwards. Think of a kettle that’s just boiled. It remains hot for a while afterwards, this is latent heat. For a thermostat, this means the temperature will continue to rise. So the system will be told to stop at 70° but the latent heat means it will still rise to 71° and then 72°.

At 72°, the thermostat will want to cool to maintain the desired 70° temperature. This could result in your system quickly cycling back and forth between heat and cool. This will increase your energy usage and possibly lead to damage to your system. Either way it will cost you more.

So does Honeywell account for this? Thankfully yes, in 2 ways.

  1. When setting temperatures for a given period, you are forced to select a range. There will be a lower temperature and upper temperature. The thermostat will force a 3° separation between these 2. This means the thermostat is less sensitive to latent heat.

  2. The thermostat has compressor protection. This locks the compressor for a few minutes after use to prevent it from cycling on again. This will protect the equipment from damage.

The overall outcome is that you have extremely accurate and safe control over the conditions in your home. Another extremely good aspect of the thermostat, actually of any Honeywell product, is the mobile remote access. We all want remote access; heck why else would we want a wifi smart thermostat?

control-from-anywhereHoneywell really deliver here. Their mobile access is called ‘My Total Connect’. What makes this really good is the way that this is been developed. Unlike other manufacturers who make the thermostat and then come up with a mobile app to control it, Honeywell actually developed mobile access first.

Well, not exactly developed it first, it just made use of its already established platform and interfaces. This meant that when they were developing the thermostat, they already knew both how it would connect and be controlled. So what does this mean to us?

As ‘My Total Connect’ is well-established and Honeywell use it for all of its products, there is a huge user network. This includes home users and business users. This means that the interface is both well tested and contains fewer bugs than what is generally seen in other apps.

Of thousands of reviews online, that I read during my research, regarding my total connect, there was only one issue that kept coming up. What was the biggest complaint? There is no auto logon feature. If that is all the people complaining about then it shows how good a platform it is.

To access ‘My Total Connect’, you can use the web portal directly through the Internet or as an app available from Google Play or iTunes. So is there a difference between these different ways to how you access your thermostat? Well yes and no.

When you use the App, in addition to being able to control the thermostat you also get a five day weather forecast. This is dependent on your location that you entered during setup. This way to control the thermostat is more basic but it is only intended for changes on the go.

When you access through the web portal you gain the ability to add more locations and additional thermostats. Which comes in handy for any holiday or rental homes you may have or if you have a multizone system.

You can grant access to 3rd parties to remotely access all or just part of your system. You are also able to set up to six e-mail addresses for notifications. These notifications are for any alerts such as filter changes or to let you know if:

  • The temperature or humidity is higher or lower for a specific amount of time.

  • The thermostat lost connection with Honeywell servers.

  • A change was not received

  • Or that the thermostat conditions have returned to normal

The combination of the App and web portal gives you full control to manage your system and to make any changes you need on the fly. Any fine tuning or additional preferences can be done back at the thermostat the next time you are there.


The only obvious thing missing from the control aspects is the ability to use Z-wave. This is a communication protocol, using low power radio waves, to network and control home automation equipment such as lighting, security and, of course, thermostats.

I find this strange as Honeywell already produce thermostats that support Z-wave, so it would have been a nice addition. But, I guess that as Z-wave uptake is still only in a relatively small % of the market then there may not be the demand. After all, the thermostat is aimed at the average consumer rather than speciality, niche consumers. No one product is going to be the perfect fit solution for everybody.

So maybe next time? Fingers crossed!


Color-3Now we get to the features of the thermostat, some of which we have already discussed. Things like fan control, as I have already mentioned, is a really nice addition.

Especially to get rid of the smells after cooking, or burning (I like to call this intentional caramelizing for flavour…that’s my story and I am sticking to it!) something really stinky. Although, if you did opt to rewire your g-wire you may not get these benefits.

Let’s be clear, Honeywell do not market or claim that this thermostat is a ‘Learning’ thermostat like the Nest. With that said it does have some really neat features that make it the true competitor to the nest. What other features are there?

Smart Response Technology

The thermostat works out how long the heating or cooling system takes to reach the set temperature. This ensures that the set temperature is reached at the time set rather than having to wait for it to catch up. This means no more waking up to a cold morning and waiting for the thermostat to reach temperature.

Auto changeover

In areas that need both heating and cooling on the same day, some thermostats need to be told to switch type. This can be a real pain in the proverbial. The Honeywell wifi smart thermostat can automatically select the correct heating or cooling setting depending on the indoor temperature. This makes the whole thing hands off, freeing you to get on with your life.

Compressor protection

If a compressor is allowed to cycle on and off all the time, it won’t be long until it burns out. This means an expensive repair bill. By ensuring that the compressor isn’t allowed to restart for a few minutes can help prevent this damage. This is what compressor protection does.


When there is a problem with your system, like replacing the air filter, or if there is a problem with a setting, a big orange button will be displayed on your home screen. This will also be e-mailed to you (if you have set it up) and also shown in the web portal (thermostat name will be red).

By pushing the button, it will give you instructions on what to do to resolve the issue. Once completed the big orange button will no longer be displayed. This means no nasty surprises for you because of a wrong setting. It also gives an easy maintenance schedule for you to follow. No more trying to remember the last time you changed a filter.

Customized Color Screen

This is a purely cosmetic feature but probably the most important to some of us. It allows you to customize the screen to any color you want. This means you can seamlessly match your home décor so that it doesn’t stand out and blends in. Or you can choose your favourite teams colors, change it by season or holiday. The actual variety is endless.

There are 12 preset colors for quick selection but there is a complete palette of colours for you to customize and optimize to your heart’s content. This is done using 3 sliders that control the color (0 to 359), Shade (0 to 100%) and brightness (0 to 100%). If you can think of a color then you can make it here!


DimensionsAssembled Unit:

Length:     114 mm / 4.5”

Height:     90 mm / 3.5”

Depth:      19 mm / 0.75”



24 bit Color, touch screen

Length:      95 mm / 3.75”

Height:      57 mm / 2.25” 


  • Simple installation (once you sort out c-wire option; see con)

  • Great app for remote control

  • Responsive and intuitive touch screen

  • Simple Setup

  • Scheduling is straight forward and quite pragmatic

  • Reliable and very accurate

  • A thermostat being a thermostat

  • Color changing screen


  • Needs a c-wire

  • No energy reports

  • No z wave

  • Quality of build (maybe?) 


PintrestOverall, the general consensus and ratings on the internet for the thermostat are positive. The main things people like are the accuracy and simple, straight forward operation. With the reliability and design of the ‘My Total Connect’ and the color customization are also rated highly.

The main complaints revolved around wiring issues for older systems without a c-wire or alternative wiring. This complaint isn’t that different to other smart thermostats that need a c-wire which is more and more becoming a staple for most thermostats these days.

Another issue is the lack of energy reporting. But as we have discussed, what is important here? Is it having a report to tell you where your energy usage is or is the end results that are the cost and energy savings? Although the addition of reports would have been a nice feature…If I had to choose, savings would win each and every time!

All in all, the Honeywell Wifi Smart Thermostat (RTH9580WF) is a solid and worthy competitor to the nest Learning Thermostat. It’s able to stands on its own merits rather than just be a clone. It doesn’t try to be anything other than a high specification thermostat. Something its user base are happy about. Its price point is comparable and can achieve the same results albeit in different ways.

What we have is a modern day, Tortoise and Hare race between these 2 wifi thermostats. On one hand you have the experienced and dependable tortoise (Honeywell) versus the new and flashy Hare (Nest). Ok this may not be a fair comparison but who will win? Unlike the parable, I am not sure. Both are excellent Thermostats so only time will tell.

What I do know is that Honeywell are unlikely to just let this go without putting up a fight.

Check out the current Amazon pricing now for the Honeywell Wifi Smart Thermostat (RTH9580WF).


  1. Robertsi December 26, 2014 at 11:09 am - Reply

    hello, great website

  2. rich December 29, 2014 at 5:05 am - Reply

    I have 2 homes and spend time in both so remote control of the empty house is important. I am retired so do not have a regular schedule. One house has the Nest and one has the Honeywell. I turned off the learning feature of the Nest because it couldn’t suit our schedule. The energy reporting of the Nest is nice but not important but knowing system status is important to me. The Honeywell shows “Equipment Status” on the thermostat but not on my mobile app. This would be a valuable feature to be able to monitor compressor stage, emergency heat, and fan operation.

  3. Alternate wiring December 31, 2014 at 2:22 am - Reply

    In order to get the fan to work when using the G wire for the C wire you must put a jumper between Y and G. Without the jumper you won’t have a fan.

  4. Best AC Repair Palm Springs February 4, 2015 at 4:45 pm - Reply

    Saved as a favorite, I really like your website!

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