Heat sensors?

I’m brand new to smart things and working to repurpose an old alarm system using the konnected system. The house has heat sensors in the kitchen, garage, utility room and laundry room; these are quite old and I don’t think can be wired to the konnected board. So, given that, wondering if there’s something else available. My Google fu is failing me except for something like the Nest protect but even that is not recommended for these areas. I have ecobee sensors in other rooms right now. I wonder if the multi sensor or the temperature probes can be programmed via rules to act as a rate of rise sensor? Or is there another option? Thanks for any help!

How is this different from a normal temperature sensor, such as used by a thermostat? Most home automation temperature sensors report once every 15 minutes: I don’t know if that is frequently enough for your use cases.

Thanks! What’s there are sensors that detect if temperature goes over a give threshold, or, more uniquely if the temperature rises more than 15 degrees in a minute (suggesting a fire). They’re used when smoke detectors are unreliable (dusty, cooking areas, laundry)

Temperature goes over a particular threshold is easy, as long is you can handle that 15 minute check interval.

Rate of rise sensors for reporting periods have a minute or so are trickier. I only know of two fairly easy options.

The first is a Z wave device which is made on the US frequency, but which is intended for commercial buildings. The company, Climax, doesn’t really operate on a retail basis. But you can contact them and see if they’ll sell you a small quantity. But I don’t know anyone yet using it with SmartThings, so it would also need a custom DTH.


The other alternative is to use an analog probe sensor and connected to one of the Z wave monitors. People commonly use this with the Fibaro RGBW controller which can take four analog inputs. This one is popular when used with probes for things like pond management.


If you have maker skills, you can essentially make the equivalent of the Fibaro controller using an Arduino, a WiFi module, and ST anything. Less cost, but more effort.

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SmartThings added a device handler recently for a z-wave heat alarm. The only device with a fingerprint is made by FireAngel

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EU Company, that one won’t be compatible with a US hub. But the DTH might still be a good starting point for the Climax, assuming you can find a unit to buy.

Iris sensors report temp changes as close as 5 minutes apart. I actually thought it was more frequent than that but I can’t prove that right now.

UPDATE: They can report in minute intervals:

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What’s the model number of the Heat Sensors?

Do you know whether the “Heat Sensors” have the internal smarts in them to detect an over-temp or rate-of-temp condition? If they did, I would assume that they would simply close a dry contact (or open a dry contact) when in alarm. If that’s the case, there should be no reason why you couldn’t hook them up to Konnected as another digital input treated as a “Smoke Alarm” input.

If the alarm logic (over-temp, rate-of-temp) for these devices is done within the alarm panel circuit board, then that logic would need to be replicated in a replacement MCU (like Konnected or ST_Anything.) This would require analog inputs, most likely. The NodeMCU ESP8266 used by Konnected only has 1 analog input.

The alarm was really complicated in terms of set up so I’m still working through which zones were which but from what I’ve deduced, the heat sensors are two wires instead of the smoke alarm’s 4 wires (which the konnected guidance says is a no go)… so that’s why I didn’t put them in the board. The detectors look really old (probably original to the 1980s house) so who knows if they even work…

These should work on Konnected as they are basically a contact switch. They don’t require power. Basically if the temperature reaches a certain threshold, something internally pops and the contact changes state from NC to NO I believe, but not positive. I have many installed in my home over HVAC equipment and one in kitchen hooked up to my Vista 20P alarm panel. These things last forever and have to be replaced only after they detect heat. You can buy new ones online if you prefer to replace them with new ones.

Another option for you if you don’t want to utilize these is you could leverage the wires going to your existing heat detectors to send power to a USB powered device where the source of power is where your alarm panel is located.

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Anyone recommend a heat detectors that can be placed in the garage/attic? I can’t find any Z-Wave heat detectors available for purchase so I am looking for something I can use with a Konnected board.

Why not just use one of the two sensors that are natively supported already by Konnected?


I have both the DHT22 and DS18B20 sensors in my attic.

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I would prefer to have the Konnected boards at a central location (where they can be powered by a UPS) and then a sensor mounted on the ceiling of the garage.

I tried extending the temp sensors you linked but after a few feet they stop communicating reliability over CAT5E.

I could just put the Konnected board and temp sensor on the ceiling of the garage and power the board itself over CAT5E but i was hoping for a cleaner looking solution.

Ahh, yea… that makes sense. You could use one of @iharyadi’s Zigbee Environment Sensors which only require USB power to operate. They do a great job of reporting temperature, humidity, pressure, and illuminance. Might be worth a look, especially if your garage has an open outlet in the ceiling that could be used to power the board via a small USB phone charger. Oh, and they also act as a Zigbee repeater!

Also, here is some detailed information regrading Dallas Semiconductors 1-Wire network design guidelines for long networks. This might be useful if you’re trying to use a DS10B20 sensor.


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The Honeywell Ademco 5809 are quite common for alarm panels. I have one over my air handlers and one in the kitchen. They use 2 wires and require no voltage as they are a use once sensor and will change NO/NC when they detect heat. You could hook them up to a Zwave sensor or to an input on the Konnected board.

Been over a year since the last post here and I would like to revisit this topic. Would like to install a heat sensor over the cars in the garage and prefer wireless (zwave). The HD-9ZW mentions here does not seem to be available anywhere for sale. It is exactly the type of device I am looking for. The wireless smoke detectors that I have elsewhere in the house are also CO2 detectors so I presume I would get a lot of false alarms when backing in the car.

So far this is the only combination that looks like it will do the job for me. The detector comes from the UK. The audio sensor will alert Smartthings.

Thanks for that response. That alarm pattern is something I would not have considered. Luckily I have not actually ordered these yet. Since the sensor comes front the UK I would not be surprised if the alarm pattern is different.

Regarding a regular temperature sensor the question is how often do they report to Smartthings? I was hoping for a sensor with the rapid rise feature.

I am amazed that something that makes as much sense as a sensor over the cars in the garage is so difficult to find.

I found a video from the UK comment and it looks like the FireAngel heat sensor alert will probably trigger the acoustic sensor. It’s actually different than the UK smoke sensor alert. You’d have to test it to be sure, but it looks possible.

Different temperature sensors have different reporting patterns, and some are configurable.

For example, the fibaro multi sensor has a default temperature report of every 15 minutes, but can be set to report as frequently as every second. However, the more frequently it reports the faster it uses up the battery.

There are smoke sensors that don’t have carbon monoxide sensors, that might also be another option.

Also, do you ever warm up the car in the garage? With the door open, of course. That might set off a heat sensor.

Thanks. I clearly have more research to do before order this combo. No we don’t warm up the car in the garage but we DO live in Las Vegas. The garage, including doors, is insulated but I don’t know what the inside garage temp gets up to when it is 115° outside. A temp sensor that trips at 135 might be too low. Guess that will have to be part of my research.

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