M20 and 298 errors.

[Jasein]

I am at wit's end with Nest products. I just purchased the Nest that doesn't try to guess your every move and just does what it's supposed to (the latest model) and it refuses to connect to my HVAC system.

I have a standard heatpump/ac unit with 5 wires coming from the blower cabinet. These are brand new 18 guage wires with a brand new 24v transformer. I can check the red wire to see voltage drop across the red and blue wires (common) and it says 24v (28v actually). The nest can't see it. I have followed the steps of disconnecting the common wire and it's exactly the same. 

I have replaced the entire cable, still the same. Replaced the transformer and wired every connection myself, still the same. Any other suggestions on how to make this more useful than paperweight? 

[CoolingWizard]

One of the things I run into now and then, is the conductor is not inserted far enough into the Nest backplate. When the wire reaches the proper depth, the push tab stays fully depressed. The exposed copper conductor needs to be straight and long enough.  I have seen if it is not far enough the the backplate register the wire, present, but the continuity point is not reached.  Do you feel your were fully inserted? If your were fully inserted and not being seen by the Nest Thermostat, the only other remote possibility is a defective backplate. 

I checked the Nest Learning Thermostat Pro Installation and Configuration guide and sadly it does not list the E298 or M20 error. I can tell you they E type error are wire and power related.  The M errors are not listed. 

AC Cooling Wizard

[Jasein]

Thanks for your reply. I have been more than careful to fully insert the wires into the Nest connectors. I even ran new 18ga thermostat cable to ensure that there were no kinks or shorts inline. Nothing has helped and the nest has never registered even one connection. 

[CoolingWizard]

This sounds like a defective baseplate.  So the thermostat does not recognize any wire is attached to the base. Sometimes it will not the wire is inserted, but cannot detect the HVAC equipment.  I would suggest contacting Goggle for a warranty claim. 

AC Cooling Wizard 

[Jasein]

I'm going to purchase another nest from Amazon and if the problem persists, I will return it. I purchased this one directly from the power company and will begin the long drawn out process of returning it. It took us 6 months to finally get Georgia Power to send it to us, I can only imagine the amount of time it would take to return it. 

Thanks for your help. 

[zoeuvre]

Hi Jasein, 

Thanks for posting here in the Community. How's it going with your Nest Thermostat? In case you have an update, let us know and we'll be happy to help.

I appreciate the help, @CoolingWizard. 
 

Best, 

Zoe

[CoolingWizard]

@Jasein ,

here is another thing you might want to check just in case. The nest thermostat has a really nice technical information including that information about the backplate we want to know if it’s looking at backplate  properly. To see  how you get to that particular support screen on your Nest Thermostat. Goto SETTINGS > TECHNICAL INFO > BASE. This will list for you the information about the backplate. The picture below shows you what it typically looks like. 


AC Cooling Wizard

[Jasein]

Although it's not clear, the Nest Termostat keeps saying that it can't connect to any devices on my Blower connector (g) and my heat connector(w). However, when I first setup my nest, it asks what the primary goal was for the Nest (which didn't really indicate that it was asking which setting to set the solenoid for. So when I skipped that question, it assumed heat. Every time I would try to cool the place the heater would kick on because it guessed the wrong solenoid state based on the fact that I skipped the question. 
So after taking it all apart, removing it from Google Home, Resetting it to Factory Defaults and starting over, it still gives me the error that it can't connect to any devices on (g) or (w) . Which we know for a fact is not accurate because it is actually working somehow. In other words, it is cooling like it is supposed to. It turns on the compressor and then a couple of seconds later starts the blower (that it says it's not connected to). 
   Though I appreciate the intent with your extensive hand-holding setup, people who acutally use technology are severely hampered by these kinds of pedantic instructions. When it takes you 50 steps to install your 5 wire thermostat, something is wrong. You need to have an "advanced" setup that cuts to the chase. And then you could just ask: Should the solenoid be set to Cool or Heat on your heat pump rather than "What is your primary goal today?" To get this really unattractive and terrible difficult thermostat to work obvioiusly.

It is working, but the interface is terrible for someoone like myself who has a problem with capacitive touch devices like this. I try to select something and it scrolls way down on the list. I spend more time trying to carefully tap the damned thermostat than I do actually cooling my house. Whoever the designer is for Nest, I hope you fire them. Every aspect of it is a pain in the ass. Even the wiring of the harness on the back...whose Idea was it to set two sets of opposing wires in the same place but facing in opposite directions> You go to pulll out one wire and you will undoubtedly pull out the same wire on the opposite side. Make it so that doesn't happen. There's no benefit to wiring it in a way that pushing to the left, accidentally pulls on the cables on the right (unplugging them). Assinine.

Alrigh, I've used up all my grumpy old white guy privilege for the month, so feel free to close this ticket. It's working now. Thanks to everyone that helped troubleshoot. I'm just gonna ignore the part about not being able to connect to the heat or the blower. 

[Jake]

Hey Jasein,

Thanks for the help CoolingWizard.

I wanted to check in and see if you managed to see CoolingWizard's post. Please let me know if you have any questions from here. I would be happy to assist, and make sure you are good to go.

Best regards,
Jake

[Jenelyn_O]

Hi everyone,

I appreciate your help, @CoolingWizard, Zoe, and Jake. 

@Jasein, checking if you still need help. Please let us know, as we'll be willing to assist you further. 

Best,

Jenelyn

[Jenelyn_O]

Hi folks,

Due to inactivity, we'll go ahead and lock this thread in 24 hours. We'd be glad to help you further so if you still need assistance, feel free to start a new thread.

Thanks,

Jenelyn

[CoolingWizard]

@Jasein 

I am so sorry your are having some difficulty.  Over the years I have installed thousands of thermostats and couple hundred Nest thermostats. I have never had any difficulty with the installation.  The goal question is simply trying to know if you’re in a heating season or a cooling season; It is that simple.

When you have a heat pump system you need to know what the default system mode of the outdoor unit is.  Perhaps you have heard of the O  mode versus the B mode.  This has to do with the reversing valve. For example O models are cooling models and need to energize the OB wire to changeover to Heating.  The opposite is true of B models. B models are Heating by default and energizing the OB wire will switch the unit into cooling mode. No thermostat is smart enough to know what default mode a Heat Pump is.   There are far more O models in service so if it is unknown by the owner, Nest Configuration default is an O model.  
Heat Pumps use the R, Y, and OB wires.  The W wire is for Auxiliary Heat.  If your indoor air handler has electric heat strips installed, the W wire would be connected to the control board and would work. The Heat Pump defrost control board in the outdoor unit would also be connected to the W wire as well. This allows the Heat Pump to keep the air warm when it is in defrost mode.  

As for the the installation of a Nest Thermostat, I feel it is simpler than the old style thermostats.  Following the installation instructions it directs you to insure the bare copper wire conductor is straight.  That you press down the tab, fully insert the wire and release your pressure on the tab. If the tab stays fully down, the wire is fully inserted.  Old style required to wrap it around a screw and tighten it.  And, in the old style, the HVAC technician was require to program it.  Google Nest is far easier.  If you lack the dexterity to tap and scroll on the  Nest Thermostat and move through the menus, perhaps using a smartphone app would be easier for you.  Everything you might want to do with your intelligent Nest Thermostat, you can accomplish with your smart phone and app that is linked to your Nest Thermostat.

I am glad to hear your system is finally operating properly.  I wish you the best.

AC Cooling Wizard, a 63 year old