Aprilaire Thermostat 8800 any MODBUS experts?

Feature Requests
42

I also have used serial to IP converter and controlled the thermostats over IP using putty terminal window just the same as using a com Port

43

While unrelated, I do find this as good news. I am finally able to control my Aprilaire thermostat with Google Home. It’s been a struggle for over a year getting this functionality to work. They have done some recent updates to their app and backend, lets hope it doesn’t break anytime soon.

44

that is cool but going to guess you have a WIFI thermostat and it is going through the cloud

45

I’m a bit curious about the level of interest here. Many years ago I wrote a driver for the 8870. The 8800 seems to be a drop in upgrade for the 8870. Home Assistant is all new to me at this point but I do plan to get my 8870s integrated.

Right now my work around is to use the climate features of my ElkM1G. The Elk has been connected to my 8870s for years and works fine but only implements a least common denominator feature set of a small handful of thermostats. I’d like the other features.

46

interested I just bought a elkm1g but can’t get the 8800 thermostats to talk to it either nor can I get Home Assistant elk intergration to work though I can connect to it via m1rp

47

Getting the Elk into HA seemed like luck to me. I think the integration’s configuration has been broken for a couple of HA releases now. I’ve tried upgrading HA only to have to roll it back. There is a bit of activity in the community here on the topic.

If you 8800’s are the same as my 8870’s you need the elk climate board connected to the thermostats data lines. The climate board expects rs232. The thermostats are rs422, so you need a converter. If you have all that, getting the four data wires connected is the next trick. Where are you at in all of this?
.

48

I have 7 8800 thermostats > 8819 > 8811 converter> m1xsp>M1 gold.

I have connected to the 8811 directly with my PC and through terminal able to send command and retrieve data from all the thermostats so to that point of connection I know is valid.

When I reboot the elk m1 the xsp led blinks with the send and receive LEDs on the 8811 then to a steady heartbeat but I am unable to send or receive anything from the elkrp interface in regards to the thermostats I am pretty sure I am missing a step I built the 4 rules as per instructions from elk named all the thermostats and made sure the numbers match though not convinced the M1 even really sees the xsp or 8811 even though I enrolled it and updated the firmware

What version of ha is known working?

49

Your setup is similar to mine. Being able to talk to the 8811 with your PC is a great sign. Typing SN? should get you a list of your thermostats. Have you checked the baud rate setting on the elk thermostat board? I know the XSP manual says it doesn’t matter, but I don’t remember (10+years since install) that to be the case. The only thing left after that is the cable. I also don’t remember (but can check) if the same cable used to connect the 8811 to a PC can be used to connect the XSP to the 8811. One might need a straight cable the other a null modem cable.

Last thing to note is that the elk is very slow to poll the 8870s for updates. I find it odd that it just doesn’t listen for changes. But if you make a change at the thermostat, it can take 3 mins or so before the elk notices. If you tell the elk to make the change the thermostat will see it almost immediately.

I’m running HA 2022.3.1, I guess I was lucky when I first tried. I had to ignore the discovered elk and do a manual add and select the unsecure option. But there was also some weirdness of needing a username/password entered, then removed on a second try, to get it to connect.

When you do get it to work, I’d suggest using the ‘prefix’ option. While it’s intended for folks with multiple panels, I simply called mine ‘elk’ and all of my elk related entities had that as a prefix to their name. I wish all integrations would do this. Most of the elks entities need to be wrapped in a template sensor to be useful, so doing this makes naming the wrapped sensors easier… but I digress.

50

I configured the xsp for 9600.
I used the serial cable that came with the 8811 as per instructions from elk to connect the xsp.
The enroll feature sees and updated the firmware of the xsp.

I can command one or all the thermostats in terminal window connected directly to the PC i know all the sn#s

I made the four rules in the m1rp as instructed to verify the thermostats and that what failed it doesn’t send the command to the thermostats it pretends it did but even the key pad says thermostat is not enabled

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51

…hmmm. I think I have one last thought on the topic (for now). I just checked the jumpers on my XSP and found that all of the baud rate jumpers are off, or 000 in their terms. So from the ‘it works for me’ school of logic, that might be worth a try.

Everything else, cable included, sounds right to me.

The keypad message sounds helpful. I tried to replicate it here and failed. If I disconnect the XSP from the thermostats it just goes on pretending they are there. Of course the status on the thermostats never changes, but that’s not always obvious. I also disconected the XSP from the Elk. The only indication I received was on the “enroll” page of ElkRP where is showed the device missing. Disconnecting an input expander, on the other hand, does show a message on the keypad. At version 5.1.8 I’m not current. Perhaps newer firmware is a bit better about reporting missing thermostats.

Oh… make sure you shutdown or disconnect ElkRP from the elk. When connected it’s in programming mode and doesnt work the same as when it’s not. I’ve confused myself for hours by leaving it connected.

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My jumpers started all on zero as well but the tidbit about m1rp connected is something I will be conscious of that when I poke at it again

53

Okay I tried to get it to talk to my thermostats with M1RP disconnected and it had no effect no command made it to my Thermostats from the Rules that the M1 Gold has even move the jumpers back to the 000 position no effect

54

2022.4.1 claims fixed issue with elk did you want to verify?

55

Finally figured out how to connect Via Serial port from the ELK M1 to Home Assistant all thermostats showed up in HA but they are dead I can get any readings or send any commands to the thermostats

Temp shows 0* I can activate various commands in Home Assistant but no changes is acknowledged at that thermostat

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56

well this was a long hard road
finally got the thermostats working through the ELK M1 Gold
this path is not a cheap one but seems to be the only path if you want to integrate the 8800/8870 thermostats
went through alot of hoops that was not need to accomplish
it boiled down to doing a factory reset on all my thermostats and they started working with the ELK
the intergration in Home Assistant works as expected so now have control and monitoring of the thermostats on the app

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57

I don’t know anything about ELK M1 Gold. Is this something you would recommend for someone without a technical background?

58

It requires a bit of technical savy and more parts than just the elk gold to connect to the thermostats the instructions are decent but not great, it is not a cheap path to get the 8800 to work in home assistant but it is the only one I found

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59

I was able to get the Aprilaire WiFi Dev kit from Aprilaire support (they give it to you if you ask, but won’t post it online) but got stuck and abandoned trying after I couldn’t get port 8000 to open on my thermostats. Since it sounds like y’all got way farther than I did, could one of you explain how to do that?

60

None of this applies to the Wi-Fi thermostat

The 8800 uses communication cable on the 422 protocol

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61

Mine is a 6000 series and uses port 7000. To enable it, you have configure the thermostat for ‘Automation’. To do this, Navigate to Menu, then press and hold ‘Contractor Menu’. It will prompt you to continue, say yes. Once in the setup menu, go to ‘Installer tools and test’->Connection Type. Select Automation. Then exit the setup menu. Note, the thermostat will be ‘Off’ when you exit the setup menu, so, don’t forget to set it back to ‘Cool’ (or ‘Heat’).

I have successfully communicated with it using documentation from Aprilaire with a C#/.NET app. I don’t know much about python or home assistant though, otherwise we would probably already have an integration :slight_smile:

Brian

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