@jwilliams89 The Energy Stats article should really be updated, it's misleading at the moment.

Has anyone been able to find meaningful information about the TriVal option on Vaillant SensoComfort / AroTherm Plus systems? It sounds like it ought to be able to do tariff or heat-source switching but that's about all I have been able to establish.

This is what they say:

Heat pumps

Almost all of our current range of heat pumps can and should be fitted with either a sensoCOMFORT or VRC 700 control.
Vaillant can offer an aroTHERM hybrid renewables heating system for those properties that have heat loss outside the scope of a
single heat pump or that have a fossil fuel boiler that can be expensive to run.
An aroTHERM hybrid system should always be fitted with either a sensoCOMFORT or VRC 700 control*, which features Vaillant’s
unique intelligent tariff selection tool, triVAI®.

What is triVAI®?

The triVAI intelligent tariff selection tool ensures a Vaillant hybrid system works as efficiently as possible. It assesses the energy use
of each part of the system, analyses the Coefficient of Performance of the heat pump, the efficiency of the boiler and energy tariff
prices. With this data, triVAI is able to select the most cost-effective heat source in the system. It does all of this automatically with
no intervention required from the user.

This smart approach to integrating renewables (either at the beginning of a building project or as a retrofit solution) offers more
flexibility and options for a wide range of properties.

triVAI®

Unique triVAI® intelligent control system Controlled via the VRC 700(f) or sensoCOMFORT (RF). There are three possible energy tariffs that
can be entered – providing maximum cost savings.

.. other than that they refer you to your installer.

Posted by: @dr_dongle

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What is triVAI®?

The triVAI intelligent tariff selection tool ensures a Vaillant hybrid system works as efficiently as possible. It assesses the energy use
of each part of the system, analyses the Coefficient of Performance of the heat pump, the efficiency of the boiler and energy tariff
prices. With this data, triVAI is able to select the most cost-effective heat source in the system. It does all of this automatically with
no intervention required from the user.

So in simple terms triVAI is designed for a hybrid system, ie one combining a heat pump and another source (usually a boiler).  If you haven't got a hybrid system (they are rare) then you can ignore.

@jamespa Hi Jamespa, I have all of those - A SensoComfort VRC720 which offers me the TriVal option, an AroTherm Plus ASHP, a buffer tank and an oil boiler. I have been running the system as a hybrid on the BiValent point since the temperature dropped and I can tell you all about it courtesy of eBus data and my own sensor network.  It works but with drawbacks and some things to watch out for. What I don't know how to do is set it up to optimise based on tariffs.

I had a good look round and even ChatGPT can't find out much more than I have already posted.

I may have answered my own question. Telling the Senso “TriVal” opens up a short menu on Tariffs in the section just before you enter the Installer code. I have read the description of the Tariff section in the Senso manual really really carefully and I *think* it tells me everything I need to know but I have to trust it or at least keep a close eye on it. I'm on the discounted OvO tariff and while that still applies then it won’t have any effect because the ASHP is cheaper than oil until you get below a COP of about 2 which is unlikely. Also the oil boiler won’t run in tandem with the ASHP if it struggles since that depends on the bivalent point – I can’t have both. I could force it to switch sooner or later by adjusting the tariff rates but It’d be nice to have a more informative manual.

A slightly different but related topic, hope 

Does anyone know if the sensoNET internet gateway is required in order to get stats onto heatpump monitor? As I get the sense the app is not essential but it would be nice to be able to probe stats. 

Posted by: @batpred

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A slightly different but related topic, hope 

Does anyone know if the sensoNET internet gateway is required in order to get stats onto heatpump monitor? As I get the sense the app is not essential but it would be nice to be able to probe stats. 

I dont know for certain about heatpumpmonitor, the kit recommended for it (see openenerymonitor) almost certainly has its own connectivity.  Openenergymonitor generally relies on separate metering not the heat pumps own metering, so logically this has separate connectivity.

I get my stats using the HomeAssistant myvaillant integration which uses the same API as the app and thus does require the internet gateway (because, like the app, it queries Vailant's server). 

I believe there is a way to get stats into homeassistant (and other monitoring tools) using eBusd and the eBus adaptor, all running locally.  However I havent tried that and I dont know anyone who has.

You are correct the app is not essential.  I do use it because occasionally its useful to check OAT or current power usage, but rarely.  It does have stats about energy over day, week, month and year which are occasionally useful also, but I think these are also available from the HPAI.  The principal differential use case is operating the heat pump remotely of course, but because I just leave mine to do its thing that is not something I need often!

Not exactly the question you asked but hopefully of some use.