In the last few days I bought my first motion sensor when I found them available heavily discounted on an online store. I didn’t initially have a specific role for the sensor in mind, but thought it worth a punt to experiment. Subsequently I’ve incorporated it into the lounge heating.

Previously the lounge heating went off at the end of the day according to a schedule set within the Eve Thermos, but could be overridden via App or Siri to extend heating if watching a late film for example, but an hourly rule disabled the heating to prevent it being left on all night so the heating may need to be re-enabled at hourly intervals.

In the new scheme the heating is extended to midnight via the schedules in the Eve Thermos, but the Eve Motion sensor is used to review heating status every half hour from 10:00 PM. The movement sensor is configured with a duration of 30 minutes so that the output is made for 30 minutes after motion is detected. The output can then be tested for either on or off. An amended rule is triggered every half hour and, if motion is NOT detected, then heating is disabled on the assumption that the household is out or has retired to bed.

The new arrangement is an improvement on the former arrangement as the heating does not need to be extended manually via the App or Siri, and doesn’t need to be renabled periodically.  It now does not need manual extension even once, let alone multiple times (at least until midnight).

For more than a year now we’ve been building up our smart home capability. There are various ecosystems of such devices, but we’re using Apple HomeKit a decision initially motivated by the presence of multiple iPads in the home.

Step	Description	Picture
1	My first step into smart home was to replace radiator valves with smart valves. Typically that results in replacing a temperature-only TRV with a smart valve with both a temperature set point and schedule. A schedule still operated within the central heating timer, but The schedule within the valve allows heating to be disabled in a particular room even though on elsewhere. Applications for this include disabling lounge heating on weekday mornings, disabling the playroom heating after our daughter’s bedtime, not heating bedrooms during weekend daytimes etc..
2	My second step was to add the ability to turn on the heating remotely so, instead of having schedules in both the central timer and the individual valves, the schedules exist only in the valves. Instead rules link the valves to the boiler so the boiler automatically runs from the first radiator valve on to the last radiator valve off. Thus, instead of potentially needing to modify both a valve schedule and the schedule on the central timer to make a change, only instead a single change to the valve schedule is required. Similarly things like extending heating in the evening, to watch a late film for example, a simple Siri voice command to the radiator valve is enough rather than having to extend boiler hours too. The hardware to achieve this is a standard smart socket, driving a relay which closes contacts across the correct terminals on the central heating wiring block alongside the boiler. The software to achieve this is two rules - a boiler on rule and a boiler off rule. The rules require a hub to which to run which initially was my iPad.
3	My third step was to add an Apple TV unit as a hub to complement the iPad. This allows the heating rules to operate even when the iPad is not at home of has insufficient battery charge to act as a hub. Extra capability from this additional hub allows control from remote locations, such as warming up the home if one will be home early or disabling vacation setting prior to starting a home-bound journey at the end of a vacation.
4	My fourth step started a completely different non-heating theme. We’d had a few occasions where family members had left the house with windows open, so I started adding sensors on windows that were most likely to the left open - typically cloakrooms/bathrooms. In this step we needed to use the Apple Home app, the Elgato Eve App, or Siri to check window status.
5	My fifth step continued that different non-heating theme with the addition of our first smart bulb, now in a lightfitting near the burglar alarm control panel. A series of rules combine both automated dusk-to-dawn white lighting and coloured lighting when any monitored window is left open.
6	My sixth step continued the lighting theme with the addition of our second smart bulb, now in the outside light by the front door. This light had an integral dusk-to-dawn sensor but this failed leaving the light on continuously. Rather than replace the whole lamp I simply added a white smart bulb. The existing rules were modified to add the new bulb to provide dusk-to-dawn white lighting. This step was added August 15th, 2018.
7	My seventh step returned to the heating theme with the addition of our first movement sensor (an Eve Motion). The purchase was prompted by a fellow member of an online community identifying that these were on sale by a well-known online retailer for under £30. I purchased it without a specific plan how I would use it, but soon identified an opportunity in the heating. In the new scheme the lounge heating is extended to run later by modifying the schedule in the Eve Energies, but then the movement sensor is used to curtail the heating earlier if no movement has been detected in half hour intervals after 10:00 PM. This step was added September 21st, 2018.
8	My eight step remained with the heating theme with the addition of another Eve Thermo eTRV. I had bought the sensor a few months ago when Maplin were closing down, but had not yet used it. However it seemed better to use it than leave it lying literally on the shelf. The chosen location was the downstairs cloakroom that had previously had a standard TRV where the radiator heated to the set point whenever any smart value demanded heat. This was the first time that I had a smart valve in the same room as a window sensor and it was interesting to see the Eve App automatically create two new scenes to pause and resume heating in the room while the window was open. I also used the valve in a way new to me - rather than utilise the internal schedule instead I switch its temperature set point when any other valve demands heat. I thus consider this valve my first 'slave' valve - simply operating from first 'master' valve on to last 'master' valve off. This step was added October 1st, 2018.
9	My ninth step was one of general robustness via the introduction of a second Eve Energy, this time used to support a periodic check of status my 'watchdog'. The Eve Energy supports a review of status every 5 minutes allowing output states to be corrected if an earlier change of state was missed and failed to trigger a rule. This is described in Dog sitting in the smart home This step was added October 20th, 2018.
10	My tenth step was a further one of general robustness via the introduction of a second Apple TV used as a second hub. This second Apple TV is placed in a room diagonally across the house from the original. The original TV is at the South West corner of the hose, which isn’t ideal for BLE coverage, but happens to be next to the TV in the lounge. While it can reach all the smart devices from th8s location, there are occasions when the signal is lost. The second location should improve robustness for the more distant devices as signals are relayed via the second hub to which whichever hub the system regards as the master at the time. The hubs themselves communicate with each other via WiFi and onwards to the devices by Bluetooth/BLE. This step was added October 29th, 2018.
11	My eleventh step was to introduce two WIFIPLUG smart plugs to control dishwasher and washing machine. The WIFIPLUG units were selected in preference to my existing Eve Energy devices due to the availability of an API interface allowing my HEMS to interact with the smart plugs. This was described wet goods project. This step was added in December 2019.	WIFIPLUG smart plug

Each rule in the smart home can consist of triggers, conditions and scenes. Triggers consist of one of more alternative events any of which cause the rule to be evaluated. The optional Conditions consist of one or more statements all of which must be true for the rule to be satisfied. Scenes consists of one or more scenes that are set when the rule is satisfied.

For my heating control I have two scenes that set the boiler on or off, and triggers and conditions reflecting the status of the radiators.

As an alternative I considered rules using temperature, but that would make things more complicated if the temperature set point is adjusted as you might need to change the rules; whereas by having rules based only on (fully) closed and (partially) open then the set point can be adjusted without issue.  Additionally you can control around a very low vacation set point for frost protection.  Effectively there are four set points:

1. Closed – which is forced by a summer setting, but also occurs at other times when no heat is demanded.
2. Vacation temperature – 5 C for me – a low set point for frost protection, but from which it might take an extended period to warm up.
3. Economy temperature – 10 C for me – a lower temperature limit during normal scheduled operation.
4. Comfort temperature – 24 C for me – a minimum temperature avoiding complaints from my wife!

My system retains the original 7 day timer, which these days I use only to control water heating.  If I did enable the 7 day timer as well as the smart controls then the boiler would be enabled when either the 7 day timer or the smart controls demanded it.

No heat this morning (not that its absence is a major issues as the weather is fairly mild). Initial analysis via the Apple Home App is that some of the radiator valves can’t be reached, and thus I assume that the rules that enable the gas boiler can’t be satisfied.

As a short term fix I could have turned on the boiler manually via the app or using the central timer which is normally set to off for space heating (but not hot water) when using the smart controls, but I didn’t need to do that as I quickly found the root cause.

I initially thought that there was some corruption in the configuration of individual valves, so I was planning to delete them from the App and then re-pair them, but then I spotted that as I moved around the house I was losing different valves, so I turned my attention to the hub i.e. the Apple TV box.

Turning on the box it appears that it downloaded a software update overnight. As soon as I acknowledged a screen describing the changes then all the valves became reachable, the control rules were satisfied, and the gas boiler was enabled.

It would be more robust if you could specify a default value in a rule to be used if the actual value was unavailable from the device.  The actual value being unavailable would also happen with a flat device battery for example.

When I first set up the smart home system I used my iPad as a hub.  You don’t need a hub at all for the individual smart radiator valves to follow their daily schedules, but the use of a hub is required for devices to interact with each other (such as a valve calling for the boiler to come on) or indeed to identify which days are working days and which are non-working days (since this is taken from a calendar). However of course this doesn’t work when the iPad is removed from the home.

The solution is to configure an Apple TV box as a home hub – enabling devices to communicate via the TV box.  This also enables remote control so a user with an iPad can operate the system when away from the home – such as disabling the vacation settings while still on vacation to allow the house to warm up.

Of course the Apple TV box can also be used to watch TV which my daughter uses to watch CBeebies or YouTube kids TV via the appropriate apps.

To date we have 7 smart devices – 6 radiator valves divided between 4 rooms, and a socket which is used to enable the boiler when any smart valve demands heat.

In my previous post I described replacing conventional thermostatic radiator valves (TRVs) with smart valves (sometimes called eTRVs).  The smart valves include both temperature set points and a schedule which allows me to operate shorter on times in rooms not used so much – such as the playroom heating turning off after my daughter’s bedtime.

My latest update is to link the valves to the boiler so that heat demand from a smart valve fires up the boiler, regardless of the settings of the older central timer and hall thermostat.  That would mean, for example, that if my wife want to watch a late film then commanding heat in the lounge would restart the boiler even if outside normal heating hours.

The effect of this change can be seen in the attached image which shows three days of valve position information for the two radiators in the lounge: two days where the boiler was enabled by the conventional timer and central thermostat, and the third day with smart boiler control.

For the first two days you can see the valve open wide for an extended period during some of which time the boiler won’t be pumping hot water as the hall is up to temperature.  However on the third day, with the link to the boiler, the valve closes very quickly from its initial position and then modulates to maintain the temperature since the boiler is running all the time when any valve is open.

The system is controlled by two rules through Apple Home:

1. If any valve moves off closed (triggers)  then enable boiler.
2. If any valve moves to closed (triggers), and all valves are closed (conditions), then disable boiler.

The picture shows the actual mechanism to turn the boiler on or off via the Elgato Eve Energy (which is a switchable mains outlet and energy meter) in the right side socket outlet.  I use the Eve Energy to operate a mains relay (in the black box) which in turn closes a contact between two terminals of the heating wiring box, which bypasses the heating timer and hall thermostat, sending a mains control signal to the dual port valve for the heating thus opening the valve thereby enabling the boiler through the existing controls.

The first evening’s operation showed two issues:

1. Room temperature was reported as overshooting in some rooms, but not in one room with a newly installed valve. It may thus be that the older valves have self-tuned their controls and need to re-tune to the new more dynamic system characteristics.
2. I needed to manually turn down the radiator in the hall which was getting too hot.  If that persists then I may need to add a TRV or smart valve to the hall.