First experiences, how does it actually work?

CsGeza

Hi,

I'm new in tado. Yesterday I have installed V3 Thermostat with Extension kit.

I have floor heating in living room and radiator heating in other rooms. I need very small switching hysteresis because the thermostat in living room and floor heating is very slowly.

I have different feelings after the first night with tado.

Setpoint was 22°C. It was still heating over 22°C, at 22.4 I have changed setpoint to 21.5°C then stopped.

I didn't find any specifications, what is the switching range? Me would be the 0.1°C perfect.

Setpoint 22C then heat on 21.9, heat off 22 (or 22.1). Is it possible with tado?

What does heating icon mean, one-two-tree heat-line?

Thanks for your help.

jacoscar

Hi, it does not work with threshold but it uses a PID controller (if you don’t know what this is check on wikipedia)
There is always a certain amount of overshoot with radiators; I don’t expect it to be different with underfloor heating; the only solution would be if Tado allowed the pid parameters to be tuned, but even if it were the case, you would have to compromise: you could avoid overshoots but it would take longer to reach the set temperature
The good thing is that if you leave it on for several hours it should dampen out the oscillations and get to a stable temperature

Vertigo

I cant help with your questions (fellow newbie here) but can I ask first, is that a iOS screenshot? On my android app I cant select a time on the graph to read the exact value like in your screenshot, which is annoying as the Y axis has only 2 horizontal division lines (17C and 20C in the one im looking at) and I just have to guess what the temperature was.

But like you, IIm also interested in understanding the "heating power". I see in openhab it varies between 0 and 100%, but my boiler only supports on/off, and I cant figure out when it actually turns on or off. Just now heating power was at 24% and the boiler ran for a bit.

I will say tado does appear to do a good job maintaining temperatures in my setup, preemptively stopping heating when the radiators are hot and getting pretty close to its target most of the time. I think it learns how your heating system works to prevent over/undershoots so perhaps you should give it some time to learn your system?

CsGeza

Thanks for your answer. ;)

Yes, it's on iOS.

Couldn't you touch area of chart and slide your finger left or right? On iOS es works in this way.

Yes, maybe need it more time to learn my heating system...?

Vertigo

PID loop doesnt explain the heater is still on when the target temperature is already exceeded. That would require a negative P value :)

CsGeza

In this way, I can hardly imagine how could be this thermostat more efficient if would heats only to 22.1C at 22C setpoint instead of 22.6C...?

Saving money was my last wish, but the comfort would be the first. But it is not comfortable 21.8-22.6 by a floorheating. :(

Maybe we have to say goodbye..? :/

jacoscar

Well, it depends what parameters they are using; generally you get an overshoot unless finely tuned

Vertigo

CsGeza, contact tado support via email. They have access to all the logs and they understand their own fuzzy logic, they should be able to help and either explain what happened or fix it.

jacoscar, overshoots in achieving the target can obviously happen, if too much power is applied for too long trying to reach the target, but in this case, power was still being applied after the target temperature had already been reached. It wasnt just residual heat from his floor causing the overshoot, his boiler was still being fired. That makes no sense and is not a PID tuning problem. No matter how badly you tune the loop or what values you use for P, I and D, at the very latest the moment you overshoot your target, the calculated power requirement should change sign. In practice its always long before if I and D are not zero, so residual heat can get you to the target. But never ever long after you overshot it.

MarkN1

This it a long term issue with Tado. There is absolutely no excuse for the heat being applied above the set point UNLESS the heating curve has peaked and is on its way back down towards the set point. But Tado consistently applies heat through and beyond the set point, resulting in a major overshoot. PID is about anticipation, not reaction. This isn’t fuzzy logic, it’s a mistake - and it needs rectifying.

GoodBranch

Hi. I agree 100% I am puzzled as to why I look at my system and see “ Heating” BUT the temperature has already been reached.

I am no techno but if it says “ Heating “ does that mean it is still heating despite being at the designated temperature?

Mistake? Never! Tado don’t do that it is your fault! 😉

Pepepua

I agree too. I think that is something must be solved. Maybe something to setup the source of heat (floorheating or air heating). O maybe posibility to switch from PID to hysteresys.

With a floorheater we have two problems:

1. Start late (floorheater take time to heat)
2. Residual heat.

If we add the described problems here, Tado is not valid for floorheater.

melchizedek

I have the same problema with my underfloor hesting. Tado Is connected via opentherm ti the boiler, i have asked support for tuning but the best result Is oscillation temperature between 16.5 to 16.9-17 Celsius with 16.7 setpoint..
I have set this temperature for all 24h/day, that Is the best solution for High inertia underfloor heating.
I prefer 0.1 histeresis too because overshoot and undeshoot on this type of system Is expensive and not comfortable.
And more because only 0.1 difference Is equal to hours of heating/Power off boiler states.
The very bad Is that with only 0.1 overshoot the system remain off many hours for power on heating when temperature Is close to 16.5 with more Power request to the boiler for reach the setpoint in an infinite costo expensive and poor comfortable loop.
Anyone have reached a solution?
Sorry foto my english :).