My Smart Home Design

Here is my smart home design. I doubt my exact design will satisfy all your needs, but may be a start for your customization or at least give you some ideas. Whenever doing any type of design–software, hardware, organization, etc.– you need to clearly define, ideally quantitatively, what you need to accomplish. Otherwise, how do you know your design does what you want? You also need to consider the effort/cost and risk-reduction trade-off if you are looking to automate to deal with some problem. It’s usually easy to get some cost-effective, risk-reduction but much harder and more expensive to eliminate almost all risk.

In my case, I wanted to protect against water damage while we are away. Water is the unsung villain causing incredible damage if not quickly cleaned up. While the water damage could be very expensive to repair (our neighbors had a $50K bill to fix damage caused by a ruptured ice maker water line), most of the damage repair bill would be reimbursed by homeowner’s insurance but there would certainly be a hard-to-quantify hassle-factor in dealing with the damage and restoration. So my primary goal is to eliminate the hassle-factor associated with water damage.

Since we travel a lot since retiring, I wanted an automatic system that didn’t depend on us being present to notice a problem or take corrective action. After moving out to live on my own, I’ve had a clothes washer hose burst in the middle of the night leading to water cascading down the stairs, a hot water tank leak in the basement, and a reverse-osmosis water dispenser leak overnight leaving a wet kitchen floor. Since we may be away for several weeks, even a small leak could do extensive damage if left unattended for weeks. But at the same time, these occurrences remain somewhat rare, happening to me three times over the span of almost 50 years. Since I live in the part of the country that has basements, I have also had sump pumps fail. Luckily, I noticed the high-level of water in the sump pit before it overflowed and could damage carpeting and drywall in my finished basement. I frantically replaced the sump pump literally hours before the airport limousine pickup and we would be gone on a 10-day family vacation. And finally, we often travel during the very cold parts of winter and need to protect against furnace failures that could lead to frozen pipes which would then lead to water damage. We have had the furnace fail, but we were home to notice the house was getting cold and got the furnace repaired before it was anywhere near freezing inside.

Luckily, I’ve never experienced the significant power outages noted in the news where homes are without power for many days after a major storm. Such situation would require a much larger battery backup (or even an automatic generator) than I have planned. Dealing with extended power outages is beyond a smart-home design. My design assumes protections against the typical few hour power outages.


These needs led me to construct a smart home design that provides 1) an immediate response for the most damaging and substantial types of leaks (e.g., an appliance hose bursting), 2) fast action for smaller, less damaging leaks, and 3) notification for problems that cannot be resolved remotely and requires calling neighbors or near-by relatives. Note that my design started from the objectives rather than from the solution.

Having multiple tiers of “smartness” in a smart home isn’t unusual and often is the most cost-effective way to a solution. While it would be wonderful to have a fully integrated smart-home solution from a well-known vendor, smart-home solutions are too fragmented right now as the technology emerges. So be prepared to do some custom integration yourself.

Immediate Detection and Response

For immediate action response, I use a leak detector with plenty of sensors and a shut-off valve directly at the appliance. I’m not looking to protect from rare failures in the copper plumbing pipes but in appliances and hoses. After doing my due-diligence, I selected the Flood-Stop brand of products. There are other brands but I have a front-load LG washer that is somewhat sensitive to water flow restrictions and so looking for valves with large internal diameters. I have had no problems using this brand of valves. I have a Flood Stop system on my clothes washer and on the dishwasher since these are easy installs to the existing supply line. Since the products come with a single sensor about a foot long, I bought extra sensors to place closer to potential leaks (such as under the washer as well an under where the hoses connect to the plumbing). The automatic shut-off valve sits between the manual shut-off valve and the supply hose going to the appliance. The sensors are sensitive and the valve closes within seconds of a leak detection. I did not put a flood-stop on the hot water tank line since it would require cutting into the copper supply line, and so not an easy install, and the water tank is in the basement near a floor drain and so less likely to cause extensive damage. The largest amount of water is in the tank so shutting off the supply line will not significantly reduce the size of the leak and I think/hope a sudden failure in a water tank is less likely than an initial slow warning leak.

I bought the right-angle valve assemblies shown below, but if I were to rebuild my system I would probably buy the straight valves and add a water-hammer suppressor (or at least I would try that). I find my front-loading washer to have fast acting water valves and can hear some water hammer when the washer pulses water when initially filling.

Though not strictly needed since the Flood Stop shuts-off the water at the appliance, I signal a leak to my overall smart-home hub which shuts-off the water to the whole house and alerts me to a problem.


Fact Action

For fast action response, I use a 1/4-turn shutoff mechanism mounted on the water supply main shut-off valve as shown below. I opted to add a motor to turn the existing valve rather than replace the manual valve with an automatically-controlled one. Changing valves would require more substantial plumbing work. When a leak is detected, the valve is closed and water to the whole house is shut off within a couple of seconds. This doesn’t immediately stop water from a leak because the water in the house pipes need to drain and the hot water tank depressurize, but does prevent ongoing water leaking for hours/days/weeks.

Eco-Net actuator installed on valve
Eco-Net actuator installed on main water shutoff valve

Note that I added a description of how to disengage the motor and manually turn the valve in case I needed to contact a relative. The picture also shows the position sensor switch (described in Z-Wave and Ring Alarm Integration) I have zip-tied to the pipe.

For whole-house operations, I use Z-Wave sensors and actuator and the Hubitat hub. It is possible to get a self-contained system with sensors and automatic valve if you want to change the plumbing valve. Since I had other potential uses of a smart-home hub in mind, I took the individual component approach and set up smart-home automation rules. Using a hub requires a bit more skill, but not really anything beyond someone that can follow instructions.

While sensors are available in both ZigBee and Z-Wave varieties, the actuator I wanted to use for the water valve is Z-Wave so it made most sense to just use Z-Wave. I use the ECO-NET valve actuator since it mounts to the valve body eliminating stress on the pipe and it has a high-torque motor (I noticed my 13 year-old valve was a bit hard to close). I have also added an external battery backup so the actuator operates during power failures.

While the Hubitat hub has it own app to show notifications on my phone, I have integrated it with my Ring Alarm system which I use for my doorbell camera.


Remote Notification

For leak notifications, I use the Ring app hooked to the Ring alarm and its matching leak sensors. I already have the Ring Doorbell camera so adding their alarm made sense; I don’t need another app on my phone and I know it is working since I get alerts when packages are delivered. One issue when creating a water leak system is periodic testing to ensure it works when needed. The Ring alarm unit has battery backup for power and a cellular backup for the internet connection so I’ll get alerts no matter what. I use the self-monitoring option since I don’t need police responding to a water leak. There may be other options for notification, but this is what I use. Once I have the Ring alarm setup, I also installed the listeners for fire alarm and CO alarm; since our townhouse has a central fire alarm system, a sensor that listens to the annunciator is exactly what I wanted. Not that there is anything we can do about a fire when remote, but we can alert near-by relatives to checkout the situation if there was indeed a fire. I can remotely tell if there was serious damage if the NEST thermostat or Ring doorbell camera no longer work.

I also have my Nest thermostat hooked up to IFTTT to alert me if the inside temperature climbs above 100F (failed A/C) or below 50F (failed heater). I would also get a freeze-warning notification from the Ring leak sensors. The integration of Nest with IFTTT is fragile since Google has “improved” their security. I didn’t migrate my Nest account to my Google account so that 3rd party integrations would continue to work. I think companies fail to understand the security sensitivity of different pieces of data. While you need to be careful about what any leaked data could expose (e.g., someone could tell you aren’t home or are asleep), I really don’t care if someone gets periodic temperature reports from my thermostat; they could easily tell I’m asleep or not home by observation. I would, of course, not want someone to remotely control the Nest.


Systems Integration

Since no single system offered everything I needed nor provided off-the-shelf integrations, using three systems required some work integrating them together. In fact, one of the biggest down-sides of Ring and Flood Stop is lack of integration with other smart home systems. Ring uses Z-Wave technology to interconnect its sensors, but is closed. Flood Stop is self-contained with no smart-home network but does provide a “contact-closure” to allow integrations. Since Ring and Flood Stop don’t provide integrations, I integrate by soldering a few wires. There are three integrations I needed: 1) between Flood Stop and the whole-house Z-Wave, 2) between the whole-house Z-Wave and Ring and 3) between Ring leak sensor and a remote sensor. These are described in detail below.

And finally, I automate the whole-house functions using the Hubitat Z-Wave hub. Using Hubitat, I have an automation rule that says to turn-off the water to the whole house whenever any water sensor reports a leak. And I have integrated Hubitat with Ring so that turning off the water is seen as a leak to Ring, which then announces the leak (I keep the keypad near my bed) and sends a notification to the Ring app on my phone. I have also integrated Hubitat with Alexa so that is another way to control the system.