Newbie - need some help to specify a startup system


Competent sparky here with home automation experience.

we have installed a single phase 13kw heat pump a grant aerona mk1 i think it is.

I would like to monitor this and work out whether its working optimally, it is controlled via a nest stat and its own ATC heat pump controller

Also i have 3 phase and neutral 100A incommer at our building plot and would like to monitor this.

the two locations are under 90m between each other and i have cat5 cable and wired network (connected to the internet) between them.

can someone please advise what emon kit i would need to purchase to get this going - do i get the heat pump monitor for the heat pump and a emon for the power?

heat pump controller is this:

heat pump this:

thanks in advance


Welcome, Pete, to the OEM forum.

Firstly, please say what you mean by “emon”. We use it as a generic prefix meaning energy monitor, so you need the next bit too!

The first thing to be aware of is all the OEM kit is designed for the common UK single phase domestic supply. So if you use an emonTx, with changed software for 3-phase, only one phase is measured accurately, the assumption being that the voltages of the other two don’t differ too much. If that’s good enough, then fine; otherwise it heads for expensive with 3 emonTx’s. The emonTx can send its data only serially (short range) or by 433 MHz ISM Band radio, so to get onto Ethernet you probably need a low-power RaspberryPi or a serial-Ethernet adapter. (The RJ45 on the emonTx is not Ethernet.)

There certainly isn’t any spare capacity in the emonTx when monitoring 3 phases to do anything else, so yes, you will need the heat pump monitor as well. I know very little about the heat pump monitor, so I must leave it to somebody else to fill in the details on that.

How do you intend to store and display the data? It sounds as if you need a second Raspberry Pi, or another server, to run emonCMS (software) that will manage the data storage and turn the numbers into web pages you can look at. As you’re not going to be using the ISM band radio, you don’t need the emonBase as such.