Tado App adm Opentherm
Answers
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I just looked at the tado account that shares your forum email address. I see a wireless receiver that is set up to use Vaillant eBus communication with your boiler, not Opentherm. The feature is sadly only available for Opentherm, not for other digital bus interfaces.
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@Rob is there any reason this is limited to Opentherm? It would be a useful feature to have, and might actually make the subscription worth having for many users.
I can't see why it couldn't be implemented in software. Surely it's as simple saying if Tado requests a flow temperature > maximum, set the flow temperature to the maximum allowed.
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@EmbattledGecko I am not a programmer, so I cannot tell you the complexity. But, in my experience, when I think something is simple to program, the reality is usually much more complex.
As support we've never been able to set the flow temperature for Vaillant eBus. Not in the backend either. We've been able to do it for Opentherm since before I joined tado 6 years ago, if I'm not mistaken.
Is it possible to set this setting on the interface of your boiler?
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I can only set the max flow temperatures on the boiler0
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@Rob For all the digital systems (Opentherm, eBus, etc), the flow temperature is set by Tado. It's what makes the digital control so great - as the house warms up, Tado sets the flow temperature lower. For example, right now my heating is running at 40°C since the house is warm. But early this morning it was running at a much higher temperature as the house was cold.
As @Leash says, Vaillant users can only set the maximum on the boiler. But I don't see why it's necessary to rely on the boiler to limit the temperature.
My point is that Tado could be made to simply apply the limit itself. Since Tado controls the flow temperature, it just needs to not set a flow temperature higher than the limit set in the app. The logic would simply be "if the requested flow temperature is greater than the maximum allowed, set it to the maximum".
As a software engineer I acknowledge that there are sometimes reasons why things are not possible. But it is infuriating when it feels like this feature could have been done on the Tado side in a few lines of code.
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So, are we saying the tado doesn't control the flow temp on the boiler?
If so, why did the instructions get me to connect it to the ebus on the boiler?0 -
Your description of digital bus interfaces is not entirely correct for all of them. It's mostly too limited. For some, a thermostat asks for a water temperature, based on the combination of the heat request and the set/communicated maximum flow temperature (and, now, outside temperature). Like with Opentherm.
With other interfaces, the thermostat is expected to communicate a heat request percentage if you will, which the boiler then translates into a specific water temperature. If we only ask for 40% heat, then the boiler will provide lower temp water then when we ask for 80% heat. These boilers might also have an outside temperature sensor.
Implementing this max flow temp feature for all digital interfaces is most certainly not "a few lines of code". For some, it is utterly impossible. Had it been as simple as it looks, we'd already have it. We'd be able to sell more subscriptions ;)
This is a major reason why customers were contacting us for the (static) maximum flow temperature settings for Opentherm boilers in the past. For Opentherm, the thermostat is expected to set the flow temperature. It sometimes overrules what is set on the boiler. For most other interfaces, the boiler decides and the boiler is expected to decide. It's a fundamental difference.
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Thanks Rob, but again I ask. Why did the instructions get me to connect the tado to the ebus and set it to d07 if it makes no use of the function?0
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It uses eBus just fine. It will modulate your heating based on your heat request. Something a relay cannot do. When you have a low heat request from tado your boiler will heat the water to a lower temperature than during a high heat request. With eBus it is likely to be more efficient and thus consume less energy, compared to a relay. Also without the optimized maximum flow temperature.
The feature we're talking about has been introduced 1-2 weeks ago and we have been controlling eBus boilers since many years.
Your boiler likely does not support Opentherm, so we cannot connect to it using Opentherm either.
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Thanks for clearing that up Rob 👍🏻0
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I wonder about something, is there an advantage using opentherm instead of ebus? I mean other than max temp being controlled directly from the thermostat (and general compatibility, like with the x models). Sadly 'round here vaillant boilers don't come with vr33 module preinstalled.
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