Can anyone recommend a temperature sensor for a copper pipe or with a probe?

Can anyone recommend a temperature sensor that can be used to measure the temperature of a copper pipe? It could also be a probe sensor which I could stick onto the pipe and put an insulation around it.

I don’t need exact values, I just want to know when my central gas heater is pumping hot water to the radiators and how hot/cold in comparison the water returning to the heater is. Unfortunately while the gas heater (Vaillant) does measure these temperatures, they aren’t exposed to HA, so I need to add smart sensors.

Ideally it’s a Zigbee2MQTT or Thread compatible device, costing less than 40 US$/EUR. But BLE or Wifi would work too. And I’m not a DIY guy, so I’m trying to prevent soldering a DS18B20 sensor to a ESP8266 board myself.


This is a bit of ‘hillbilly’ tech :wink: however you might have a look at this BLE device, as it ‘meats’ :wink: your no soldering requirement. Would require a ESP32 device (maybe not need the esp32, as the ‘theengs gateway’ might be able run on your Home Assistant server if it has a available and accessible BLE adapter, however I like keeping my HA server as simple as possible so the ESP32 route) to translate the BLE to MQTT or HA API’s but that gives you range extension options as well. And this device has local display, multiple inputs and fairly low cost. Good hunting!

Will this work for you, supported by HA INKBIRD - Home Assistant

No personal experience with it, but I have used other Inkbird successfully.

You don’t need to. I use screw terminals to connect my dallas temperature probes via breadboard to a d1 mini.

Nice thing is that you can hook many probes to just one esp when needed.

David, thanks a lot. While the Gove B5055 or H5055 does not seem to be available in Europe, I will expand my search to meat thermometers, I didn’t think of these before. What I’m a bit unsure is if they will be able to properly measure the range of 50-70°C (120-160°F). And also, if I find another meat thermometer with Bluetooth, if it is compatible with HA via a bluetooth proxy on a ESP32 or only with a proprietary app.

Oh, that’s a nice find. The INKBIRD IBS-TH1 is available in Europe, supported in HA and doesn’t cost a lot. As you’re using other Inkbird devices: Is the gateway that is sold extra necessary to connect it to HA?

Thanks. It’s intriguing, I also found my tiny Atom ESP32 fascinating. I just currently have so little time that such experiments will have to wait – there’s a big advantage of a device which will work the moment I put in a battery.

I have no experience with the WiFi hub, it looks like it would do Bluetooth without it.

This would have the benefit of being HA-native (esphome), and possibly powered by 24VAC if that is how HVAC/boilers/etc are powered in Europe? However, it might be a bit over your budget as you will need to buy the probe.

With the sensor I would think simply putting it in contact with the pipe, and a few wraps of tape - the heat in the pipe with the water flow and copper conductivity will easily overcome the thermal mass of the temperature sensor quite quickly.

Bummer on the Govee availability, I’ve had very good experience with several of their thermometer devices, especially those which use AA or AAA batteries, very long time between battery changes, good temperature and humidity range/accuracy and very good BLE reception distance. And good temperature ranges. Here are the specs for their meat thermometer, 0 to 300 degrees celsius. As was noted by another poster, Inkbird has some devices available in EU, with similar specs and price points, however I cannot speak for the decoding in Home Assistant. The one linked below looks similar to the Govee unit, 2 input, AAA battery, relative low cost and Home Assistant compatible according to the HA web site. Good hunting!

I strongly agree, my three Govee indoor thermometers with AAA batteries are impressive and their measurement frequency is higher than the Aqara temperature sensors I have in most rooms.

Nice find. Unfortunately I just realised that the probes of a meat thermometer are too long (and not flexible), so I cannot place them in direct contact with the copper pipes (see the red arrows):

Hmm, this is trickier than I thought. I was hoping there’s a purchasable temperature sensor where one can plug in an external probe with a clamp.

Thanks. It’s not ideal as it isn’t battery powered and I don’t have a plug in the room with the boiler. The boiler is probably using 24V, but I can’t see where I could connect anything to it – plus, I shouldn’t tinker with the boiler as I’m only renting the apartment and if there’s any issue with the boiler, the apartment owner can easily say that it’s my fault. So all I’m daring to do is to add a temperature probe, especially if it’s a “regular purchase” and doesn’t look like a DIY which the apartment owner might also not trust.

Yes, even my hacked up setup where I am using the probes in my Air Fryer, they are a bit too long. In ‘theory’ these are standard thermocouples, however beyond my pay grade to figure out of what type they are and how to replace. Think they are thermocouples and not something like a more standard temperature probe such as the DS1820 type probes as they can handle 300 degrees vs 125 degrees.

All that said, what was a ‘low cost’ idea quickly becomes not …

This might be a replacement of better size, link 1 below, however not sure it is worth wasting USD 10 and time on to try. You can get the inkbird ‘knock off’ probes on Aliexpress for pennies, and try to tear them apart. But again probably not worth the PIA.

If you can find it on your turf, going with two of the Inkbird IBS-TH2’s that @Kdem pointed to might be you best option, they are USD 24 on USA Amazon, so no too bad a price, link 2 below.

Good hunting!

As there are 9 Inkbird temperature sensors with similar names, here’s what I found out about the “IBS” devices:

  • Only the “IBS-TH1”, “IBS-TH1 Plus” and “IBS-TH2 Plus” support external probes
  • Only the “IBS-TH1” and “IBS-TH2 (not: the plus version)” are supported by the integration

So there’s just one device that overlaps: I’ll order the TH-1, even though it’s the oldest device and more expensive than the others.

I’ll let you know if it works. Or if it doesn’t. :slight_smile:

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The Inkbird IBS-TH1 works great (combined with a Atom Lite M5 ESP32 Bluetooth Proxy), I can finally see what my gas heater does, here’s the flow temperature:

(Unfortunately I know have the confirmation that the heater has too many and too short heating cycles. Reducing these is the next project.)

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maybe too late for you but if the Vaillant has an e-bus terminal (my 10 year old does). they you can get a ~$20 ebus to wifi adapter and get the values direct from the boiler itself.

For anyone else looking this is the item:

Home Assistant has an e-bus interface, so you can connect to it/decode it etc. This is also a useful blog article about (another) person who conneted their Vaillant to HA.

Oh, thanks, that’s a very interesting information, especially as this device is not yet out of stock. I will need to check if they deliver to Europe and also where I could connect to EBUS. I know my Vaillant Ecotec Plus is using EBUS, but I’m unsure where I’d find the two wires to connect to. And for insurance reasons I cannot connect anything to the inside of the Vaillant because if anything ever happens the insurance might claim that it was my tampering with the Vaillant. But if there’s a connector I can plug it in, it should be less of an issue.

there is a simple 2 screw connector on the vaillant board. I can’t comment on your insurance situation but the boiler is designed to be e-bus controlled and always has been…