Should Your Thermostat Be Cloud Connected?

This article represents my own opinion and may contain affiliate links. Please read my disclosures for more information.

The idea of a wi-fi enabled thermostat that you can control remotely through your smart phone or computer is very appealing. Unfortunately most of the wi-fi thermostats I've run across have one major flaw. They require the use of an internet or cloud based system for remote monitoring capabilities which leads to a lot of problems and concerns. I've had my Honeywell Wi-Fi Programmable Touchscreen Thermostat RTH8580WF installed for over a month now and here are my issues with not only the Honeywell thermostat but other similar thermostats that can only be used with a 3rd party web service.

Cannot Access Thermostat Directly

The biggest drawback is that while the thermostat can communicate on your wireless network, most of these cannot be accessed directly. The Honeywell RTH8580WF I own for example is not accessible on my local home network.

It took me a while and some effort getting the thermostat installed because I needed to run a new thermostat wire to connect the C wire but after that everything was going well. Then Superstorm Sandy hit my area. I wasn't hit as hard as others but I did have some damage to my home and other issues to deal with.

Luckily I didn't lose power but I did lose phone and internet service. I spent most of the day after the storm assessing damage, taking pictures, watching workers, cleaning up debris, doing some maintenance and temporary repairs.

That evening I crawled into bed cold and tired. I was about to step out of bed and head down to my thermostat to raise the temperature until I remembered I have a thermostat I can remotely control with my phone. As I was reaching for my phone I remembered my internet service was down due to the storm. I had just installed the thermostat the previous day, spent time and money (close to $50 for fish tape, wire and transformer) to get the thermostat installed before the storm hit and now the first time I really wanted to use it, I couldn't. It was a real let down.

All the other devices on my network worked fine, even wi-fi connected ones such as my phone. I was able to upload photos and videos to my media server from my phone all day. These thermostats that require an external web service cannot be remotely controlled when the internet connection is down. Even if you're connected to the same local network.

This was a big dissapointment for me because I had planned to develop some software to monitor the temperature in my home. At some point this functionality may be available through the Total Control Comfort website but it's not there yet. Even if it does get added to the portal I'm still not comfortable letting a 3rd party have access to personal information such as my home's temperature.

Privacy Concerns

The web based portals that allow remote control of the thermostat also appear collect information about your schedule, indoor and outdoor temperature as well as any changes you make to your thermostat. In the case of my Honeywell thermostat, it was sending information to Honeywell's webservers over 100 times a day.

While the connections appear to be secured by SSL and the web service is password protected there is always the possibility that the information can be accessed by those not authorized to do so. Knowing how you set your thermostat can allow someone to guess when you are or aren't at home. The information can also be accessed legally if subpoenaed. What happens if there's a crime committed and someone misidentifies you at the scene? You claim you were home alone when you would normally be at work. Instead of raising the temperature you put on a sweater or stayed in bed sick. Authorities request your thermostat history and sees you didn't increase the temperature which may poke a hole in your alibi in some people's eyes.

These may seem far fetched but could be a big problem if they ever happen to you. There are other ways that the information may come back to haunt you.

Targeted Advertising

In the connected world we live in, information is very valuable. Think of a company like Google. It provides a free service to the masses but it uses the information it gathers from those users to make billions of dollars. They monitor usage and search patterns to be able to provide targeted advertisements which advertisers are happy to pay for.

The same can be done with your cloud based thermostat. Does your home take longer to heat up than other homes in your area? That might be valuable information that can be sold to local contractors in your area or other service providers and they can even know the best time to call. Does your thermostat schedule indicate you work at night? More advertisements can be tailored for you. 

But your phone number is on the National Do Not Call Registry so you don't have to worry about that right? Wrong. Any company you currently have a relationship with can call you unless you specifically tell them not to. All it would take was for your thermostat service provider to do the calling on behalf of third parties or they might just send you junk mail.

Carefully review the Privacy Policy for the thermostat you choose if it only has an option for web based access. Unfortunately this information is not provided when you make the purchase.

Possible Future Fees

Honeywell's Terms of Service indicate that they have the right to charge a fee for use of their web based portal. Another company already has instituted a monthly fee to remotely control the thermostat. Whether fees are charged or not will depend how much money the company can make off the usage statistics and other personal information it gathers. All the internet connected computers and employees it takes to run the web portal aren't free.

If the web portal ever gets discontinued for whatever reason or fees are instituted that you do not wish to pay, remote control of the thermostat through the Internet is gone.

Needs A C Wire

This isn't such a big drawback, especially if you have a newer HVAC system but in older homes it may require running additional wiring. My original thermostat only controlled my heating system and used 2 wires. I needed additional wires to run the power to the thermostat. The thermostat draws too much power to be run on batteries solely.

I contacted the manufacturer of my heating system and they informed me that it wasn't recommended to run the C wire off the 24VAC transformer. They claimed it would increase the load on the transformer and might cause problems including premature failure of the transformer. That meant buying an external 24vac transformer for the thermostat. Between the new wire, transformer and fish tape it wound up costing me close to $50 to run the new wires to install the thermostat. That's with doing all the work myself. If you hire an electrician or HVAC contractor to do the work, you'll have to pay labor costs.

Other Options

I don't like the idea of sending out my home's temperature information to someone else thousands of times each month so I was glad that the wi-fi features of the thermostat could be disabled. 

After looking around it seems the only wi-fi thermostats that allow you to access them directly are the Homewerks Radio Thermostat CT-30-H-K2 and CT-80-H-K1 wireless thermostats. Homeworks even provides an API that makes it easier to develop your own applications for them.

Hopefully the other thermostat manufacturers like Honeywell do the same.