I’ve noticed that most of the time my ONECTA reported outdoor temperature is lower than that shown on the heat pump monitor. Is this a feature ?
I believe the outdoor temperature data on emoncms’s heat pump monitor app, is pulled from a local weather station. Whilst the temperature reported by Onecta is the reading of the sensor built in to your heat pump monobloc unit.
Two things to note:
- The heat pump reported temperature is probably inaccurate as it is sited in a location whose ambient conditions are affected by the heat pump itself.
- The heat pump responds to the temperature data of its onboard sensor, i.e. when adjusting flow temperature to the weather dependant curve (unless your system has the optional external sensor installed and configured for use).
Met office figure for this area shows 4 degrees right now, I have a thermometer on top of outdoor unit reading 2.9 degrees. Heatpumpmonitor shows 8.3 !!
That is weird, my numbers are always close on Onecta and HPM, but that’s probably because I use ESPAltherma to collect outside temp from the HP, and send it to HPM! But they are always within rounding error - see photos.
I don’t know what HPM does if you don’t give it a number - as suggested, could be local weather station.
Your HP thermometer could even be faulty, might be worth getting it checked.
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which is what you want , so the flow temps match the curve based on actual outside temps
Right now the outdoor temperature is 16 according to ONECTA, 17 according to HPM and 16 according to the Met Office. That’s a whole lot better than when temperatures were much cooler. Something is not right.
I’ve noticed the Onecta reported water temp is sometimes 1-2C above the MMI reported temp.
You’d think they’d share the same sensor?!
The outside temp sensor is always 1 degree below the online temp reported for out area.
It’s in a very secluded north facing area.
The latter means that heat pump logic thinks it should be working harder than the house needs, but only by a bit.
Would be good if Daikin had included an offset for that like the Madoka temperature.
If you have the extra outside temp there are two which can be reported
R1T = which is the temp sensor on the HP
&
R6T = which is the sensor for the extra sensor for WC normally on north side of house , you need to switch this on in the MMI if it has not already
the names are a bit confusing
the sensor on the HP can swing very quickly with fan speed and build up of frost
I’m definitely on R6T (external sensor) in the MMI.
Guess the internal heat pump sensor is much too much of a rollercoaster… but used for it to sense it’s state / control.
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