@Wayne-TP 

 

Thank you Wayne, These are supported features they just haven't been implemented properly.. It needs fixing! At the moment the KE100 is at best a TRV controlable via an app... It should be a direct competitor to the Tado system, which right now is far superior because it works exactly as the KE100 'Should'. TP are missing a trick here simply because you have not implemented the features correctly. All the bits (no pun intended) are there! You just need to put them together properly. Look at the image below from 'Your App' you can clearly see that something changes to change the wavy lines from Orange (Heating) to Grey (Not Heating) I suggest that this is the feature you call 'Mode' currently labled 'Heating & 'Off'. The data is there!! Implement it. I am so very close to selling these devices on ebay (because they don't work as they are supposed to) and buying a Tado system.

  @richrobuk 

 

Hi Mate - i have been using google home script editor (i guess you are too?).

 

I have written a script or script(s) (i am not a developer but managed to pick this more simplified coding up) that does the following for example:

 

- @6pm turn "on" bedroom TRVs - set to "heat" mode and set temperature to 18C

- If any of the relevant TRV (e.g. in bedrooms) ambient temperature is lessthanorequalto18C set Nest Thermostat to "Heat" and Temperature Setpoint to 20C

- When all bedroom TRV's ambient temperature reach 18C set Nest Thermostat to "Off" and Temperature Setpoint to 16C.

- I also have a script the turns bedroom TRVs off in the morning and tuns on the TRVs in the living spaces e.g. lounge etc.

 

This seems to be having the desired effect - e.g. controlling the boiler and not having to rely on the nest thermostat temperature which is in the downstairs hallway and somewhat irrelevant to the upstairs bedrooms - is this what you are trying to achieve?

 

Here's an example of the code if google home script editor (can only be done on the web version):

 

One of the issues i'm having is, the Kasa TRVs seem to shut off the hot water prior to reaching the desired 18C - probably expecting the radiator to continue heating the room up for a little while. In some cases the room does not then hit the 18C and my boiler doesn't shut off, bit annoying but can probably tweak this by setting the TRV setpoint to say 19C but the boiler to turn off when all TRVs hit 18C or something.

 

Let me know if you'd like some help doing this?

  @JMRewop 

Using Nest Thermostat for this isn't optimal, as you manipulate its temperature setting instead of controlling the boiler directly. I'd suggest to replace it with simple NO/COM smart switch (no voltage), or if boiler allows, an OpenTherm controller or similar compatible device.

Also your automation is based on TRV temperature setting & reading, instead of real heating status. Which it reports, but not to Google Home.

Thanks  @Trobalabau 

 

Using Nest Thermostat for this isn't optimal, as you manipulate its temperature setting instead of controlling the boiler directly. I'd suggest to replace it with simple NO/COM smart switch (no voltage), or if boiler allows, an OpenTherm controller or similar compatible device.

 

Thanks for this - that's an interesting point; i just push the nest thermostat temp up which calls for heat - do you think this is a big issue or just minor? I don't fancy making a massive change as it sorts the hot water etc.

 

Also your automation is based on TRV temperature setting & reading, instead of real heating status. Which it reports, but not to Google Home.

 

Thanks for this - it seemed to be the only option. Presumably temperature is what we are looking for here, is the room hot enough yes/no etc.? 

 

Thanks for your response/interest.

  @JMRewop 

Nest is totally redundant when you want to have something more capable. You can't turn on the boiler directly because it's not exposed to IoT system yet. Instead, you manipulate Nest settings to get this result. I'd strongly suggest to get rid of it and get a relay compatible with your boiler. You don't need "thermostat" anymore when your entire system takes its role (automation for TRVs, sensors, boiler control). As of now, with Kasa TRVs Home Assistant seems to be the only option to make all of these work together.

 

My boiler is quite old so by connecting wires (NO/COM switch) I can only control if it's on or off.

There is some interface for weather sensor to adjust heating curve (water temp) automatically, but it's proprietary and hard to find, I'd rather wait for new boiler. Now I can change e.g. the "out" temperature of the water only on its control panel, while OpenTherm device should probably expose it for IoT systems as well. 

 

Regarding hot water for bathroom etc. it depends how it's configured. My simple boiler does it by itself, using thermometer installed in the water tank. I just set the temperature, but of course it's 24/7. Water heating has priority over room heating.

I don't know how Nest is related to water heating. Maybe you connected thermometer to it, and then via OpenTherm it tells the boiler "hey, heat the water"? If so, then I think proper OpenTherm replacement would be needed, or rewiring to use boiler's internal logic.

 

 

Regarding TRV heating status, check Tapo app as unlike Kasa it shows it accurately. With Google Home, Matter, Kasa app it's either off (frost protection), or "heating" regardless if the room temperature is high enough with valve closed, or if there's heat demand with valve open. As of now only Home Assistant can tell you that difference by hvac_action "heating" or "idle" and lets you make automations based on this.

It's the same as with Nest - your current logic must make assumptions based on temperature delta etc. instead of checking the actual devices.

 

While hvac_action is more accurate than comparing the temperature values, it still will show you "heating" e.g. when it almost reached the room temperature target but already closed the valve (even completely) to compensate for remaining thermal capacity.

 

Of course it's not ideal yet with Kasa, as valve opening percentage is not exposed in any way so we still cannot bypass TRV's internal logic of manipulating water flow in the radiator. Well, we can try to do it like with Nest and set extreme temperatures to enforce 0/1 opening, and then try to make better logic. For me, current Kasa room temperature fluctuation is just fine and I don't need it to maintain more stable and precise value. But there are others who complain and want to know or even control valve opening percentage themselves.

  Hi @Trobalabau 

 

Thanks for your robust response - really interesting to read about your view and your setup.

 

I will review what the options are for replacing the nest thermostat. Re: hot water, my nest basically just calls for hotwater once per day for an hour which causes the zone valve to the boiler to open and the hot water to be heated. I'm sure this could be replecated by an "on/off" switch. 

 

It sounds as though i could push things on quite a bit in a number of ways - i've thought about jumping across to Home Assistant previously... just strikes me as a bit of work to get up and running!

 

Cheers,

  @JMRewop 

Water tank heating should definitely be temperature-based, not just time. My boiler switches the room/water heating circuits automatically with its internal valve, while yours seems to be one-function, with water tank as just one big "radiator" in the same circuit, right? Then I'd definitely recommend OpenTherm or similar as these modes require different heating power & temperature that needs to be changed on the boiler.

  @Trobalabau 

 

I should've said there is a thermostat on the water tank so if the water reaches 60C or whatever, the boiler shuts off until the temp drops again in the 1hr window.

  @JMRewop 

60 in the water tank means that temperature in the (single?) circuit is even higher, likely not very energy-efficient. Condensing gas boilers work better in much lower temps, heat pumps can't even go that high. Consult your whole system with a professional.

Thanks for this - as i understand hot water should be stored at 60C+ to at least to kill legionella bacteria - from HSE. The circuit temp can be changed by me via the boiler.. can't remember what its set to!