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True Radiant timing not as described

Phoibos
Community Member

I installed a Nest Learning Thermostat a few weeks ago to control our steam heat system, which uses radiators.

My understanding of the True Radiant function is that the thermostat learns how long it takes to reach target temperature and for how long the temperature will rise after the boiler is shut off. Based on that, it will start the boiler before a higher temperature set point in the morning so the temperature is at least close to target at the scheduled time.

After several weeks, my thermostat may start the boiler 30 minutes early, but still takes another hour or so to reach the target. Even worse, approaching the night time set back, it will still start a heating cycle less than 20 minutes before the set back goes into effect, with no chance of the system warming up enough to have an effect. A total waste of energy.

Settings are:

Auto-Schedule: Off
Time-to-Temp: Ready
True Radiant: On, Ready

What am I missing here? 

1 Recommended Answer

Phoibos
Community Member

To continue the saga: I just received another email from a low-level customer service avoidance rep (as that appears to be their function). I’m being told the system works as intended and he used a scenario that does not reflect what I’ve been reporting at all. 

Here’s a screenshot to demonstrate what I’m talking about

CA589D6F-0CA5-44A7-86AC-8E34227ED29E.jpeg

 Schedule is: 8:30 AM - 19C, 0:30 - 15C

As you can see, the system claims that it started heating early to reach 19C by 8:30. But it did not reach target until 10AM or so. This hasn’t changed in months. Maximum pre-heat time is set to 5 hours so there are no limits that prevent it from turning on earlier. 
But what irks me more is the little blip on the left. Despite “knowing” that the temperature will drop to 15C at 0:30, it will turn on the boiler minutes before that time. As it takes at least 30 minutes for the radiators to start warming up, this is futile and a waste of energy. 
And nobody at Google/Nest is willing to acknowledge this, not to mention address this. 
I think it’s time to take this to the utilities that offer rebates for energy saving appliances and let them know they’re wasting money on something that doesn’t work. 

View Recommended Answer in original post

26 REPLIES 26

Jhonleanmel
Community Specialist
Community Specialist

Hi Phoibos,

Thanks for posting and sorry for the delay ― let's get this sorted out.

A few questions: since when has this been happening? Also, what troubleshooting steps have you done so far?

Best,
Mel

This seems to never have worked right. I’ve gone as far as removing the thermostat from the account and resetting it to factory settings but that doesn’t seem to clear the learned behavior. 
In the History view, tapping on a temperature will show a message about starting early to reach the temperature at x:xx but the graph shows it didn’t. 

I should add that I am using a temperature sensor in a different room to trigger the system, not the temperature at the thermostat. That shouldn’t affect how the system works but who knows. 

Jhonleanmel
Community Specialist
Community Specialist

Hi Phoibos,

I'm sorry to hear that you're still having an issue with your Nest Learning Thermostat. We'd like to take a deeper look into this — could you fill out this form and let us know once you're done?

Thanks,
Mel

Just entered all the same information again in that form. 

Is someone actually going to address this issue now?

Wow. I did receive a response and it didn’t address anything I wrote. If this is the customer support you provide, I’m sorry that I invested in a Nest thermostat. 

Joeyb1156
Community Member

I have a separate thread in the forum regarding the exact same problem. The true radiant feature does not work. I’ve done enough research, and what I’ve observed, is the fact that it never goes into learning mode. The true radiant feature says on/ready, and never goes to on/learning mode. My biggest problem is the fact that it’s overheating my house by 2° to 3°. The true radiant feature was also to learn how long it takes the system to reach the target temperature and then turn off the heat early. It’s actually running my boiler 15 to 18 minutes beyond the target temperature. Totally burning more fuel than necessary. It is a serious software issue. If you search this issue on the Internet, you’ll find that there are numerous complaints in this forum as well as other places, regarding the true radiant feature not working. And it’s also been an ongoing issue for years. I am also waiting on a response after filling out the form as instructed. This issue needs to be reviewed at their engineering level. I’m not so hopeful that this will happen.  Looks like I’m stuck with a very expensive hockey puck at this point. I’m probably gonna go out and buy a cheap Honeywell thermostat.

Phoibos
Community Member

I agree, the True Radiant feature is not working as described. I believe it is learning a little but not as intended. For example, my heat does turn on a but earlier than the scheduled rise. But only maybe 15 minutes. It takes 30 minutes alone to get the radiators to warm up, so the target is reached about 1 to 1 1/2 hours late. It appears to shut off heating a bit early so the residual heat can do the rest. But the biggest complaint is that it starts heating within the last half hour before the nightly fallback, with no chance to get radiators to warm up (and no need). 
I’m still waiting to hear back but since more than a week has passed, I’m not terribly optimistic. 

Yes, sounds like yours is partially working. I am located in US and this feature doesn’t work at all. I even bought a second third generation thermostat to test and it behave the exact same way. The true radiant feature would not work at all. Where are you located? From what I have read the nest thermostats in Europe, are different in terms of how they were installed.

In the US, same as you. 
I tried a full reset, I tried with and without self-learning turned on. I adjusted pre-heat time duration. Nothing ever made a difference. 
This looks like a real bug to me. But given how unresponsive their customer service is, I suspect they don’t care much. Google probably acquired Nest because the look fits, and then told them to save money on support and sustaining engineering. 
Did you notice that they seem to close the ticket every time they send you a response, no matter what it is? Even if it’s a follow-up question? That makes their open ticket count look real good…

Well, sounds like yours is partially working. That’s better than mine, which doesn’t work at all. Out of curiosity what part of the world are you located in? The European version of this thermostat hooks up differently than the one I have, which is North American model.(I’m in the US) I even went out and bought a second third GEN thermostat to test and it did the exact same thing. The true radiant feature did not work as advertised and it consistently overheated my house. 

Well, I’ve had it with this thermostat.  It is grossly burning more heating oil than necessary. The run cycles are just absolutely horrendous. I just went through the steps of completely wiping the thermostat removing the apps from my devices and starting from scratch. The true radiant feature still will not go into learning mode. My boiler is running 45 minutes to an hour to keep my house at 64°. It is still over shooting the temperature by 2° to 3°. This thermostat is completely useless. I reinstall my old Honeywell, RTH 230 B. it is running my boiler 18 minutes or so to maintain a 64° temperature. It’s a shame that google bought nest and ruined this product. Their customer service is horrible. I opened a thread here on the forum the specialist sent me the form to fill out, and I have yet to hear back from them. This true radiant feature is not working correctly, and has been an ongoing issue for years. They have no intention on fixing this! And you are right they typically try to close all these threads out on here, so nobody can reply. That’s exactly what they did to my thread after they sent me the form. Then there’s no way to follow up with the community specialist. That’s their solution for a problem that they don’t wanna deal with.

I just heard back from them and guess what: the “specialist” assigned to this is “on leave.” So I got bunch of further instructions how to turn stuff on and of and how to reset the system. And some irrelevant questions. 
You are right - Google turn Nest into a Mess. And it’s a shame!

Let me guess, the person who reached out to you is the same old type of low level customer service rep that we dealt with over the phone. They are just reading through a generic script of troubleshooting with no understanding of the product. 

Phoibos
Community Member

To continue the saga: I just received another email from a low-level customer service avoidance rep (as that appears to be their function). I’m being told the system works as intended and he used a scenario that does not reflect what I’ve been reporting at all. 

Here’s a screenshot to demonstrate what I’m talking about

CA589D6F-0CA5-44A7-86AC-8E34227ED29E.jpeg

 Schedule is: 8:30 AM - 19C, 0:30 - 15C

As you can see, the system claims that it started heating early to reach 19C by 8:30. But it did not reach target until 10AM or so. This hasn’t changed in months. Maximum pre-heat time is set to 5 hours so there are no limits that prevent it from turning on earlier. 
But what irks me more is the little blip on the left. Despite “knowing” that the temperature will drop to 15C at 0:30, it will turn on the boiler minutes before that time. As it takes at least 30 minutes for the radiators to start warming up, this is futile and a waste of energy. 
And nobody at Google/Nest is willing to acknowledge this, not to mention address this. 
I think it’s time to take this to the utilities that offer rebates for energy saving appliances and let them know they’re wasting money on something that doesn’t work. 

I just got off the phone with a senior support rep. He says he is able to escalate the problem up to engineering. I guess we can wait and see. I have a few questions for you though. What device are you using to run the nest app android or Apple? Also, when you are in the app, does your true radiant feature say on/ready or on/learning? This is what I believe to be the root of the problem here.

They told me they elevated mine to engineering, too. Then they told me that person was on leave and I was back to the customer avoidance rep…

I’m on iOS and my app says True Radiant On / Ready. 
When you look at the screenshot above, you see that it believes it is doing the right thing (“Started early to reach 19° by 8:30”) It even appears to start a bit early, maybe 15-20 minutes) but it never starts early enough to reach target temp at target time. 
Let’s see how they try to get rid of you now. Good luck! Keep us posted. 

So, just as I suspected. The problem is the fact that the thermostat is not going into the learning mode on that true radiant feature. You turn the true radiant feature off and back on, it should be going into ready/learning mode. But it is stuck like mine in on/ready mode. I’m going to troubleshoot this a different way. I’m gonna go out and buy a cheap android tablet. Reset the thermostat and try to set it up with the android tablet and see if it behaves any differently. This could be a software bug between Google nest products and iOS.

That would be interesting to see. 
Update on my end: another email from Customer Avoidance telling me that the problem must be with my heating system and the Nest is performing exactly as it should. The elevation to engineering seems to never have happened. 
I’m starting to wonder whether they still have an engineering team at all…

Any luck with this?

No, the customer service rep contacted me back a few days ago. I need to reply. He apparently has everything kind of confused. As I explained, my thermostat keeps missing the target temperature and overheating my house. He replied back and said he spoke to the engineering team and now he’s asking me questions about preheating. I am not using the preheating feature. I have it set to max duration of 0. 

Phoibos
Community Member

Some additional information on this subject:

"Support" convinced me to delete the existing schedule and put the thermostat into learning mode again ("to isolated the issue"). Since I now had to perform all the target temperature changes myself, this led to an interesting discovery:

All the time estimates for how long it would take the heating system to reach target temperature were off.

An not only off by a few minutes, but massively off target. The estimated time was typically less than 1/3 of what it would actually take to reach the target. This was especially pronounced in the morning when the system came out of the nightly setback. The estimates for time to temperature were consistently less than 30 minutes when it actually would take 1 1/2 hours to warm up the house.

A faulty time-to-tempt estimate would also explain many other reported malfunctions of TrueRadiant. Like @Joeyb1156 reporting his house overheating. In that case, the estimate for how long it will take likely is always to high.

Unfortunately, I still have to see any interest by Google Nest in fixing this. My worry is that the lost the original developers during the transition and now don't have anyone who actually understands the code...

Yes, I replied back to your earlier post. And I have observed the same thing regarding the time to temperature being massively off, my boiler heats pretty quick. With a cheap Honeywell thermostat in order for it to maintain its temperature on a normal day. The run cycle would normally be around 15 to 18 minutes. But with this nest in place, it’s taking more like a half hour or more. It’s crazy when I’m sitting there watching the thermostat and it’s almost right at the target temperature and it will then say time to temp is under 20 minutes. But yet it’s almost right at the target temp or has already hit it. And I believe you are correct regarding their engineering team. They probably have nobody there who really understands this product anymore. Far as the physical build of the nest thermostat, it’s top notch. But when it comes to the software, it’s absolute garbage. I’ve been searching around on the Internet to see if anyone has hacked it with software that able to be flash to it. I’m sure at some point there will be somebody who will come out with that.

Phoibos
Community Member

I have also tried resetting the thermostat to get it to learn again. Despite removing it from the account, deleting the app, performing a factory reset, creating a new account and setting the thermostat from scratch, it still would use the old TrueRadiant data! 

I have provided “support” with all the data indicating that their product is defective. The latest response was that my heating system is likely not compatible. 

I am now at a point of serious outrage. Google just refuses to take any responsibility for their product, knowing that it is defective and just placing blame elsewhere. 

I have done all those same procedures as well. But I also went a step further and deleted my Home from the  Google home app. Seems that the radiant features is a little bit better, still overheating my home and the time to Temp is completely inaccurate.  I believe the whole problem is the fact the thermostat does not indicate that it’s ever in learning mode for the true radiant feature, and the time to temp feature. They both indicate just ready.

Phoibos
Community Member

I received a refurbished thermostat from Google after going back and forth for many weeks. The replacement unit did NOT show any “learning” indication either, but it IS preheating now so it reaches temp at the desired time. 
What appears to be a true software bug is that it will start a heating cycle just minutes before the nighttime fallback, with no chance of even getting the radiators to warm up. Massive waste of energy, and the short cycle is not good fir the equipment. 
But I don’t believe there’s anyone left in their R&D who could fix this, sadly