True Radiant to turn off heating early

[lobster]

Hi -

I understand that one of the feature of the True Radiant option with a Nest Thermostat is that it turns it off early to help prevent overshooting the target temperature.

Thought I saw the over side of this feature work (it starts heating on early to help my home warm to a scheduled temperature on time), I have not seen the turn-off early in action. And indeed Nest overshoots the target temperature.

For instance, my target is 18.5°C and it's overheating to 20°C. That's annoying because I experience these temperature swings that the True Radiant feature is precisely supposed to avoid / limit.

How can I adjust the True Radiant setting for the earlier turn-off?

Does the algorithm need more time to learn my radiant system pattern?

What's the development status of the True Radiant algorithm for the earlier turn-off?

Thanks!

[SuperFreq]

I also have this issue with my hydronic radiant in floor heating system.  It would be nice to at least have the ability to limit how long it will heat for. It will regularly run the heat for 3-5hrs to try and bring the temp up by 1 degree f which will of course overshoot by 5-6 degrees f and make the room too hot to sleep in.
I don’t feel that the “time to temp” learning has learned anything. It seems to trigger the heating on a threshold temp and then tun the heat until it sees the temp change occur and this is a bad way to do radiant heating. The only feature I do see seems to be for “pre heating” the furnace. 
I really hope there is a mode that I am not aware of that can help this problem. 

[07MC07]

I have a Nest Learning Thermostat (3rd Gen) and I am having this same issue.  My heat is set for 68F and it's currently 71F as I write this.  The True Radiant never has seemed to do anything for shutting it off early.  If we could please have a way to adjust the threshold or for this algorithm to be fixed accordingly.

[Grantmk]

I’ve also got this issue. Its been installed for 5 months so presumably no longer learning. I can set it to 22 degrees centigrade and it sometimes gets as high as 26 degrees. Has anybody found a solution?

[SuperFreq]

The best way I have found to deal with this so far (and “best” is used loosely here) is to set the same temp for every hour of every day. It has shown to be a bit more consistent for me. I use a temp that is 2 degrees F below what I want. The bad part is when you change the temp it requires changing 24x7 temps and this sucks. 

[Splotsmum]

You can copy and paste your daily schedule so you only have to change it once 

[mtd]

One year ago I purchased 4 of the 3rd gen Nest thermostats to run my new 4 zone hydronic radiant heat embedded in a concrete slab. This was a very expensive upgrade to the old style (dumb) thermostats originally installed. The sole purpose for investing in the more expensive 3rd gen was to benefit from the "learning" algorithm and shut-down early.  I have True Radiant enabled and the target temp set on a fixed daily schedule. After 1 yr, it appears it has learned nothing. With every variable fixed (no manual adjustments, doors open, windows shut, etc.), it appears the thermostats have not learned how to shut down early at all.  Every day it over-heats by 5 degrees! The fact it overheats consistently means theoretically I could just turn down my target by 5 degrees and hit the target every day. But after spending so much on these "smart" devices, I'm struggling to accept that solution. After all this time, I just opened a ticket with Nest support and shared this topic/thread. I'll report back if I hear a good answer. 

[mtd]

UPDATE - Good news...something has clearly changed. I did open a ticket back in the spring but support was poor. Instead of troubleshooting, I was requested to completely wipe and reset all my devices. Since I was about to turn off heat for the summer, I chose to do nothing.

Now that the cold is back, I've had our heat on for the last 6 weeks. And miraculously, the thermostats have been nailing the target temperatures. Sadly I did not take note of the firmware at that time, so I'm unsure what changed. But I'm happy to report its working far better now--lets hope that doesn't change.

[Grantmk]

Agreed, I've had no satisfactory response to my ticket but it is no longer heating up 5 degrees above the target temperature.

[Joeyb1156]

Which firmware version are you currently running? And is your true radiant feature still working?

[mtd]

Yes, the thermostat has continued to hit the target accurately this winter season. Which is a huge improvement compared to last season. All four thermostats (model Display 3.6 Backplate 5.4) are on software 6.2-27 (updated on May 4, 2022). 

[Joeyb1156]

That’s the firmware I’m running. My thermostat doesn’t work correctly at all. I even went out and bought a second one and it behave the exact same way. What country are you located in? I’m in the U,S therefore our models are different. that may explain why yours works and mine does not. Definitely a software bug.

[mtd]

I'm in the U.S. too. I guess it is possible the support agent did do something on the backend when I contacted them in May of 2022. 

I do have a slightly older model on my account, that runs a force air heater upstairs so wonder if my previous data was impacting it. Any chance you have older data in your account, or is this your first Nest thermostat? 

Likely worth contacting support and be ready for them to suggest resetting to factory -- although that seems pointless considering you have new devices.  

[Joeyb1156]

I have a third generation new thermostat. I’ve never had a nest product prior to. I am very tech and I have done all the troubleshooting. I’ve reset it back to factory numerous times. I’ve also gone in and deleted the app and deleted my home from the Google app. I don’t know what more can be done on my end to get this to work correctly. 

[Olafmol]

The solution is simple: buy another brand, because TrueRadiant on Nest simply doesn't work as advertised. It's not learning anything. There are other brands with much better algorithms.

[Etienned]

I would really want to know what those other brands with much better algorithms are?

[Grantmk]

Drayton Wiser for one.

[Etienned]

Thanks for the info. Unfortunately I'm in Canada and, if I'm right, Drayton Wiser is only in EU.

[Olafmol]

In the US and Canada Ecobee, for global/EU there are Tado, Netatmo, and good old Honeywell

[Etienned]

Thanks for the reply. I'm in Canada so my options are Ecobee and the old Honewell. By my readings on different forums, it looks like the Ecobee is not doing miracle either with cast iron radiators. Old Honeywell look to work fine with them, but I can't find information on why (a special mode, etc.)? And the thermostat is pretty big and ugly...

[Olafmol]

No thermostat will create miracles, unfortunately. As an iron cast radiator owner I would not hesitate to go for Ecobee.

[rjaimes88]

Honeywell has had heat anticipators for a long time. Even the newer ones have features like max cycles per hour that make it more suitable for steam boilers especially, but good for radiators in general. Nest was created by coders in San Fran where they have mostly forced hot air. I think they're still missing the mark for radiant heat, especially steam. The other problem Nest has is that it doesn't keep track of when the steam is created. For example, it can get close to boiling water but not make steam and turn the boiler off if the schedule changes, wasting all that fuel. Not smart.

heat anticipators:
https://www.ydr.com/story/tech/2017/01/08/nest-thermostat-long-term-review/96120870/