After lots of deliberating, multiple quotes and heat loss surveys, and a canceled Octopus install, we are about to have a Vaillant aroTHERM Plus 7kW installed next week by an independent heating engineer. He is HeatGeek Assured and is using the VitoEnergy platform / MCS Umbrella. So I am excited and optimistic that it is going to go well!
I am going to ask my electrician to install an Eastron SDM120 electricity meter, that I already own, in the feed from the consumer unit to the heat pump. So I can track energy consumption.
If I wanted to participate on HeatPumpMonitor, do I need to buy a heat meter?
Can I get data out of the aroTHERM via ebus instead? Is that significantly less accurate?
I am interested to see how it performs but maybe not spend lots of time optimising it.
Hi Nicholas! You can get all relevant data via ebus, however the temperature sensors on Vaillant units can be problematic, which can lead to significant errors. See the thread here:
Electricity metering on the Vaillant units is highly accurate, so this only impacts heat measurements. I also have an arotherm 10 kW unit and am running a “hybrid” monitoring where I combine ebus measurements with my own temperature readings.
Depending on your technical skill level and - maybe more importantly - willingness to invest time, an independent heat meter would be the best option.
Make sure it’s a modbus version if you want to be able to read data from it.
If you think you might want a heat meter installed, it’s much easier to get it in when the system is first being installed:
We offer a pre-provisioned monitoring bundle including a heat and electricity meter:
Or you can just get a heat meter on its own, or source one yourself from elsewhere. But make sure it’s got MBUS if you want to be able to read from it:
Annoyingly the “Axioma Qalcosonic E4 Heating & Cooling Meter M-BUS DN20 QP2.5” isn’t currently in-stock. So I ordered the “Sontex Superstatic 789 Heat Meter M-BUS QP2.5” instead, which was a bit more expensive.
I meant to report back on how I got on. My heat pump install completed on the 11th October and then I got emonCMS monitoring of it up and running on the 12th November.
Feeling frustrated by my lack of outdoor temperature sensor, I decided to look into using weather data instead. I am aware of @glyn.hudson’s metoffice-emoncms.
However I don’t believe you can get historical data from the UK MetOffice API. I found that you can get temperature data from Open-Meteo back to 1940! And you can even export the data as CSV and timeformat=unixtime - making it very easy to import into the EmonCMS console.
