Temperature and Humidity sensor


The new temperature and humidity sensor looks like a good gadget to have especially cause of the HTC algorithm which will take its data along with smart meter data to measure heating efficiency of the house.

Would the use of algorithm be free for limited time and we will have to pay later for its use ?



  • Thanks @rodee13 - we are working out the charging structure for the algorithm going forward but for the next weeks it is free.

    Once it is a chargeable service it is likely to be in the range of £15/year - and you can query it as often as you like during that year as you implement energy efficiency measures to assess their impact.

  • Will there be an option to provide data from existing sensors?

    I've had a Shelly H&T for a year recording temperature and humidity data. I'd rather not have to splash out on another device, but the HTC algorithm looks very useful.


  • Hi @iainmbarker - we don't have the resource to support ingesting another source of data unfortunately - and I don't think Build Test Solutions are geared up to support direct customers. I can check if you like? I think they will charge £45-50 for the service if they do provide it directly.

  • Hi @janeatglow will the temperature and humidity readings from the sensor be available in the CAD local MQTT dataset?

  • I have set up the sensor and can confirm the local MQTT dataset contains the temperature and humidity values. I use them for display in my Home Assistant.

  • Thanks @rodee13 - and sorry for delay in replying @ianm - we've been busy writing bids recently and hadn't picked up the forum thread!

    To confirm, the sensor data is in the local MQTT dataset and will also be in the APIs once they've been onboarded onto your account. The first step is the set up of the sensors, second step is to onboard to your account.

    This will be automated end to end - but not quite there yet!

    We'll let you know when it is all in place.

  • Thanks @rodee13 and @janeatglow got it working in Node-Red and HA via MQTT

  • Excellent! If you've any advice for fellow users - please let us know as well add it to the glowmarkt site guides, thank you.

  • edited March 2023

    This thread on the Forum has some advice on how to add the T&H sensor to the output from an MQTT broker in Home Assistant:


    It worked for me after a bit of tweaking of the code. If you've already set up MQTT and a Glow CAD in Home Assistant you will already have some code in the config YAML file for the smart-meter sensors which will include the MAC address of your CAD unit, or in the CAD unit itself you can find the MAC address of the CAD (in the menu under Display/Details) and for the T&H sensor under Metering/Sensors. With those two bits of info you can add the sensors to the config file by updating the code given in the thread with them (leaving out the colons (:) from the MAC addresses).

  • Thanks very much @Seliaks - as a matter of interest, here is some accuracy data on the sensor - we'll get all of the above into glowmarkt ASAP.

    • Precision Relative Humidity Sensor
    • ± 3% RH (max), 0–80% RH
    • High Accuracy Temperature Sensor
    • ±0.4 °C (max), –10 to 85 °C
    • 0 to 100% RH operating range
    • Up to –40 to +125 °C operating range

  • @JaneatGlow - I find that the Glow T&H sensor compares very closely with the Sonoff SNZB-02 T&H sensor I already have in my living room, and provides its data much more frequently, which is good. Interestingly though, the temperature sensor in my Vaillant vSmart thermostat in the same room, same location is pretty accurate in the 18.5-19.5°C range, but at lower temperatures the temperature it reports appears to get progressively further below the value reported by the Glow and Sonoff sensors, so it's about 0.4°C below at 17.5°C.

    I'm not that interested in the Humidity readings myself, perhaps I should be, but I assume they get used in the HTC calculation. On that point, the Glow T&H sensor is not yet showing up in my Glowmarkt account or on the Bright App, but I guess you are catching up with the backlog.

  • Hello @Seliaks - the humidity sensor is not part of the HTC calculation but is a sensor we included in the device for other purposes. For example, in social housing it could be useful to distinguish between underlying damp versus other issues.

    Interesting to hear what you say about the readings from our sensor versus the Sonoff sensor - the underlying sensor we use is meant to be accurate to +/- .4 degrees - down to -10 - so I'm not sure how we'd know which of the two devices is more or less accurate....

    The Glow sensor should now be in your account - sorry for the delay. We are dropping everyone an email today to confirm.

  • @JaneatGlow - I think you may have misread my comment - the Glow T&H sensor agrees very closely with the Sonoff throughout the temperature ranges. It's the temperature sensor in my vSMART thermostat, which controls my central heating system, that becomes less accurate (reads low) at lower temperatures compared to the Glow and Sonoff. This doesn't surprise me that much, as the vSMART system (by Vaillant) certainly doesn't seem that smart in practice - it's supposed to have weather and load compensation, but the flow temperatures it requests from the boiler don't appear to reflect this, and the underlying algorithms controlling its choices don't seem that stable.

  • @JaneatGlow - thanks for adding the sensor to my Bright account - I have been able to generate an estimated thermal performance value, albeit that I'm a bit shy of 21 days of data yet - it's nice to see that my house is in the 'Good' category at 1.6 W/m2/K, considering its age. Something that would be helpful for me to understand/compare the result - is there a way the HLP value can be used to provide an approximate equivalent EPC score? Thanks

  • @Seliaks - sorry for the delay - I'm not good at keeping up with the forum regularly. Presumably you are at the 21 days now - I believe that once you get to that your SmartHTC score is presented in the context of the equivalent bandings. As this isn't our algorithm we are learning together on this one - and asking the Build Test Solutions team lots of questions!

  • edited April 30

    Dear JaneAtGlow,

    I am interesting in measuring the heating efficiency of my house. Instead of buying glowmarkt temperature and humidity sensor, would it be possible that I supply my indoor temperature and humidity via API to glowmarkt instead?

    For those interested, you can see my boiler real time performance here:


    With some experiments and context here:


    Many thanks

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