Smart Things as an electric heater controller?


(Alex Ivaylov) #1

Hi guys,

I am new to home automation so please bear with me :slight_smile:

I really like the idea of the Nest Thermostat but I don’t have central heating so I cant use it. Instead, I use electric heater fans that plug straight into the mains.

I was wandering if I can use the multi sensor to get the temperature and then use the smart plug to turn it on and off automatically?

Can I do things such as set an IFTTT recipe when temperature is under 20 °C to switch on and when it’s 25 to switch off?

What about making it only do it when I am home? And what if I just want to turn it off?

What if I want to increase or decrease the temperature? Is there an easier way than editing the recipes?

And what if I get an Amazon Echo? Can I tell Alexa to change the temperature or to just switch it off?

I have looked everywhere for something like the Nest Thermostat that would work with electrical heating fan but couldn’t find any. Do you guys know any solutions?

Any help or advice will be greatly appreciated.

thank you very much


(Benji) #2

As far as I know, so long as you can find a smart switch (NOT DIMMER!!!) that is capable of the wattage the device consumes (with some comfortable headroom ideally) you should be okay.


(Glenn Brockett) #3

[quote=“Alex_Ivaylov, post:1, topic:56571”]
Hi guys,

I am new to home automation so please bear with me :slight_smile:

I really like the idea of the Nest Thermostat but I don’t have central heating so I cant use it. Instead, I use electric heater fans that plug straight into the mains.

I was wandering if I can use the multi sensor to get the temperature and then use the smart plug to turn it on and off automatically?[/quote]
You certainly can, there is a virtual thermostat somewhere around here that will allow you to use the multi sensor as thermal input and allow you to set the thermostat. This will let you use any app that needs a thermostat.

[quote]
Can I do things such as set an IFTTT recipe when temperature is under 20 °C to switch on and when it’s 25 to switch off?

What about making it only do it when I am home? And what if I just want to turn it off?

What if I want to increase or decrease the temperature? Is there an easier way than editing the recipes? [/quote]
Any of these can be done once you set up the virtual thermostat. Many apps for that, they treat the virtual thermostat as if it were a slightly smart one.

[quote]
And what if I get an Amazon Echo? Can I tell Alexa to change the temperature or to just switch it off?[/quote]
I have the echo, but haven’t tried it yet, YMMV.

[quote]
I have looked everywhere for something like the Nest Thermostat that would work with electrical heating fan but couldn’t find any. Do you guys know any solutions?[/quote]
Use the heavy duty plug in switches as mentioned above.

Here is a virtual thermostat solution that someone has worked out:


(Ray) #4

I would not use Smartthings as my main controller for heaters. It’s not reliable enough for the task yet. Also using the Aeon temp sensor is also not a good idea either. You won’t get the result for sure. Go with a third party thermostat or Nest with Aube electric heater relay. This way when ST cloud is down. You won’t be left in the cold.

Aube relay


(Alex Ivaylov) #5

Thank you very much guys!

How bad would ST be for this? How bad is the temperature sensor? What if I use the Netamo weather station or some other temperature sensor? How frequently does the cloud service go down? Is there a button on the smart plug that I can just press to switch it on/off?

That relay is exactly what I am looking for. However, from what I read it needs to be installed inside the wall but I can’t do that as it is a rented property. Is it possible to install the relay outside of the wall? Like in the box of an extension cable or something like that?


(Kevin [Yorkshire UK]) #6

Some electric heaters have an inbuilt temperature sensor and I would really recommend that approach rather than a ST coupled temperature sensor arrangement. Some of the oil filled electric radiators even have time switches inbuilt but putting the electric heater on an appropriately rated ST controlled switch would be possible although not something I’d recommend. Be very careful about the usual safety worries if the heater could be switched on when you are absent (obstruction, clothes etc etc) and if you have kids or pets that might have moved things then I really wouldn’t entertain this.

Any radio or powerline controlled socket could come on at any time by accident… although with some systems this seems to happen more frequently than others :wink: - Switching high output electric fan heaters via a not 100% reliable automation system is something I would discourage. Those oil filled electric radiators are much safer I think and would also provide a much more reliable solution and I think they may be even cheaper to run (not sure)…

Re-reading your post I see you are after an ‘at home’ switching rather than a timer or ‘remote’ app switching so that will be safer, assuming your ‘at home’ is detected by a sensor that doesn’t false trigger with pets for example. Is there by any chance an alarm system on the property that you could use the ‘set’ output on to interlock the heaters to off ? I suppose a presence sensor on SmartThings could be used for this too.


(Alex Ivaylov) #7

No, I am not after an ‘at home’ solution. I want it to switch on automatically and heat the house before I arrive at home. I only asked about the on/off button as a back up option when ST cloud is down.

The heaters that I will be using do have inbuilt temperature control sensors that make them turn on/off automatically. I will set those to a temperature that is a bit higher than the temperature that I would normally have. That way if ST doesn’t turn them off, they will turn off a bit later themselves. On multiple occasions I have forgotten them on and left the flat and there has never been any problems (touches wood). I don’t have any pets or children but I will be looking for a smart fire alarm. I will post the final set up here once I know what I will be buying.

thanks a lot


(Steve) #8

I would consider re-viewing your setup to reduce the complexity and increase reliability - always start simple with the aim of reliability then build on that. I would remove the multi sensor from being able to control the heater, and just use the thermostat built into the heater. Why? Because the multi sensors are not perfect and can crash (granted, few and far between, but why duplicate a sensor when there is one which should be very reliable built in?), or not update quick enough leading to high temperature swings.

I would be inclined to set it up the heater on a smart socket only, with the following automation options:

  1. Presence detection. If away, set the Goodbye Routine to switch off the heater (this will not prevent the heater coming on though, just turn it off)
  2. Presence detection. If returning, set the “I’m home” routine to switch on the heater
  3. If your timings are predictable, set a time based routine to switch on the heater so your room is toasty warm for when you get back.
  4. You have the option to control the heater via the app (or a Do button in IFTTT for example)

that way, you can get a feel for it, and see if you wanted to improve on anything. You could use the multi sensor for example as an method to ‘emergency shutdown’ the heater in case the room gets too hot for example (IE thermostat failure)


(Alex Ivaylov) #9

The problem I have with the build-in sensor is that the temperature is never right. It is always either too cold or too warm and I have to adjust it all the time. The reason for that is that the sensors are on the heater itself and I am usually located on the other end of the room. I was hoping to get some sort of smart sensor on the other end of the room that could solve this problem. I also want to be able to say to Siri or Alexa to increase the temperature when I am cold without me having to get up. I am also paying a fortune every month for electricity and I was reading that the smart sensors can help reduce the bill. You are saying that the ST multi sensor is not fit for this purpose and I should only use it as emergency shut down. I like the idea of the Nest and the relay so I will do research if I can install it without modifying the property.


#10

You might as well just get a basic outlet with thermostat.


(Steve) #11

I would personally not use a multi sensor myself given my experience (nor would I use ST for the job of heating directly, hence why I bought Honeywell Evohome, but that’s another story…!).

I would suggest with my plan above first and see how you get on with a basic on/off function, but take a look at this:

There are other zwave/ZigBee based thermostats on the market which would be better suited for the job and should give a more accurate reading. Whilst not a Nest/Hive, it should do the same job and work directly with ST rather than having some sort of iffy, possibly unreliable bridge to sit in-between…


(Greg) #12

I agree with most people here.

Given SmartThings has a tendency to do random things like turn the lights on when they’re not supposed to, their isn’t a chance in hell I’ll be using it for anything such as controlling heaters or unlocking doors anytime soon.

It’s just not stable enough and it’s asking for trouble


(Alex Ivaylov) #13

Hi Guys,

I decided to try the virtual thermostat so I bough the smart plug and the multi purpose sensor. It turned out to be as bad as everyone expected. In the beginning it took a few days to figure out that it should use Celsius and not Fahrenheit. But then it started doing the opposite of what it should do. I will wait for it to turn on the heating untill i am freezing so then I say to Alexa to turn it on. It goes on then I will find a few minutes later that the virtual thermostat smart app turned it off. And I tried very high values thinking it might still be in Fahrenheit but it would still just turn it off. Then it will get very warm but it won’t turn it off. So I would ask Alexa to do it but then the smart app will turn it back on. It looked like it was thinking this is cooler rather than a heater but I tried all the possible settings, combinations and values in that smart app but it just won’t do what it is supposed to.

So I gave up and I bought a Nest thermostat and I bought a relay from my local electrical shop. Here is a video I made
https://www.youtube.com/watch?v=5k7B0Qwip5g
One thing to note is that the European version of the Nest (also sold in the UK) is different than the US one. The cable codes are different and the nest operates boilers on high voltage (230v) unlike the US one which operates 24V. My first thought was that I can just hook the radiator to the Nest but the maximum amps for the nest is 3A while the radiator works out around 8A. So the relay I bought from the electrical shop was 230v on both circuits (unlike the 24V US relay).

I have also added that and set it to an arbitrary high value that never gets reached. So together with the build in thermostat, the additional plug and the Nest I have 3 things that can cut the temperature if it gets too high. I have also added a few fuse plugs and surge protection.

I am planning on adding the Nest fire alarm. I am also planning on adding more motion sensors and some sort of smart camera (probably Nest again) but I just read this


Does any one know if Nest is vulnerable?

Other things I bought are the Philipps Hue ceiling lights together with Iris (which I love) and an Amazon echo. I have also bough a Raspberry PI and I have installed homebridge on it. Homebridge now lets me talk to the Nest and my Sony Bravia smart TV from my Apple Watch or my iPhone/iPad. Siri can actually do more things than Alexa. I can ask what the current room temperature is. I can ask what the target room temperature is. I can set Nest Away mode on or off. I can also ask Siri to change the Hue lights colours without involving IFTTT. I can also ask her to turn on/off the TV an change channels or volume. I haven’t tried to add Smart things to home bridge but I think there might be a way.


(Steve) #14

Thanks for the feed back…

In theory it should work, but as you found out its just not as reliable as a proper thermostat.

It could be the code you were using as well not playing ball… did you look at the debug logging whilst running through your testing to see where its falling over? I have found this incredibly useful in the past, even with something that’s meant to be simple can turn into a nightmare!


(Alex Ivaylov) #15

It was the smart app that I got from within the smart things iOS app.

No. I am a developer myself and I was planning on looking into the code/logs but I never had time for that. I also realised that I was having to first fix the virtual thermostat and then I had to build an Alexa skill if I wanted her to control it without going in the app all the time. And then I took your feedback from this thread into account and decided it’s just not worth it and it will never be as good as a Nest.

I have to say I am very glad I went with the Nest. The temperature in the room is now perfect - never too cold or too warm. And it’s probably too early to judge but looks like the electricity bills have went down compared to what they used to be normally. I am now in the process of planning on getting a powerful electric radiator and a Nest for my other room.


(Glenn Brockett) #16

I finally set up a virtual thermostat in addition to my CT100, The virtual is merely to run a circulator fan moving heat to the back of the house if the front is 3f warmer. I don’t worry about having it run/not run when it shouldn’t be, it’s just an 8" fan and insulated duct.

I would trust the Nest or CT100 to work as a proper thermostat, as they run independent of the network, merely taking commands when sent, the actual control is internal. But the backup thermostat is a good idea, maybe I will recycle the one I had used for the circulator for this.