Rheem Econet HVAC Control Integration - Reward offered!

I’ve been working on getting my parent’s home automated via Smartthings, and it seems they’ve bought the one furnace that you can’t easily integrate into smartthings (or any automation hub for that matter). It’s a Rheem Econet HVAC unit, and instead of working like a traditional thermostat it uses two wires labeled E1 and E2 for data instead of triggering relays (it also has an R and C wire). The cool part? It provides a ton of system information and warning of potential issues. The bad part? It seems like Rheems execution leaves much to be desired. While it is possible to wire it in the traditional way, they’d be giving up a lot of features, and given that the conduit running to the thermostat is only 4 wires (and this would need at least 6, likely 8 with there humidifier) it wouldn’t be able to use much of the features like two stage heating and cooling.

Anyway, the furthest I’ve gotten so far is I was able to track down a Wifi module (REWRA630SYS, Comfortgurus.com had it for under $100) that allows control through the App and browser interface. It works, it even work pretty well from my experience. Unfortunately there isn’t a single hub or cloud service on the market that will work with this system. In the past, the Econet hot water heater control has been integrated into Smartthings but it seems that the API changed and the project died. It also only mentions hot water heaters (my parent’s doesn’t use “econet”)… in fact nearly everywhere I look, even Rheem’s website and documentation, there’s hardly any mention of HVAC control.

So, I would like to reach out to the community and ask for your assistance, but I realize this is something that very few people are stuck with, I’ve found exactly one post on these forums that asks about it, and only one or two mentions of it anywhere on the net. So, while I wish I had the skillset to tackle this myself, it’s far from it. Instead, I figured I’d offer a reward, or bounty… I’m not sure how difficult this request is (I’m willing to offer as much help as I possibly can in regards to testing/anything else), but I was thinking maybe a $50 Amazon Gift Card? $100? Cash? I’m open to suggestions and negotiation…


The Rheem Econet system uses a proprietary system. I cannot even find another thermostat head for the system. It MAY be possible to use a Raspberry PI and reverse engineer the signals to make an interface. But that sounds like a lot of work to me. I did find one reference for the API, but it’s application level, and likely the old version.

Thank you immensely for looking into it, I’m wondering if the HVAC control is considerably newer than the hot water heater (which came out in 2014)… The very few references across the interwebs that I do find that reference HVAC are all fairly recent (within the last 4-6 months), I’ll discuss it with the technician that’s coming to quote me on a new system myself tomorrow (NO ECONET). I think I’m leaning toward the direction of pulling new conduit through and wiring in a more traditional fashion to something like an ecobee or similar. I can always revert to the E1/E2 method in the future if support is implemented.

I can speak to the simplicity of the wiring, the “module” is likely identical to the other two modules but it connects to the system via a pretty janky RJ11 terminal box, a resistor (I don’t recall the value, I can double check) and marking on where to wire 3 of the 4 wires in series (E1, E2, C - which has the resistor, which I’m guessing notifies the system that a wifi module is attached…)

I also just now had a thought that I need to explore further but I’ll throw it out there… I wonder what would happen if I connected the standard terminals up to an Ecobee/traditional thermostat, and left the E1 and E2 connected to the control panel (thermostat) but move it onto the side of the unit in the basement to prevent tampering. I wonder which device would have control over the other, or if I could set the Econet into some kind of mode or series of modes/settings where it only monitors the system, this would not only provide fault/error notification anywhere but it could also provide a secondary setting verification. Better yet, if I could do away with the Econet control panel/thermostat all together that would be great, most of the benefits of the E1 and E2 data connection with all the features that traditional systems provide… I’ll do some experimenting and report back. I’ll also see if the module sold at home depot will work with my HVAC system. I’m curious, as I paid $100 and the modules at Home Depot are $50ish… all that would be necessary to use on hvac would be a resistor and RJ11 pigtail.

Looking at the information that the head unit reports I am thinking that E1 and E2 are data lines (One in, one out) with a common for power or ground. For an advanced system like this you would need more than 3 wires for control.

Looks like Rheem has announced that Econet now works with Nest, this may help…


Only on select water heaters. Although it seems to indicate an API is being rolled out.

I have the wireless EcoNet device on my 50 gal water heater. Not too impressed with the water heater itself as it seems to run out faster than my old 40 but I did toss in the wireless add on, since the rebate covered the cost. All you can really do is just adjust the temp and set vacation mode, but the book claims there is a leak sensor and other diagnostic sensors that it reads and reports on behind the scenes of the app itself…

The temp control is limited by the physical dial so if the dial on the water heater is set to 130 degrees you can only turn it up that far. If you want to control the entire range you have to keep your manual dial all the way up. (bit too risk for me with a toddler)

I could try to get a wireshark pull of what’s being sent when I make temp changes, not sure if it would help anyone or if its been already done.

I know this thread is a year old but has anyone had success integrating with the Nest thermostat? I spent a small fortune on a Rheem HVAC system last summer only to find out after install it only works with Rheems EcoNet thermostat. The EcoNet is awful and not user friendly. I would be willing to pay someone to tell me how to bypass their “proprietary” system and use another smart thermostat, preferably one that can be controlled with RBoy.

Here’s what it says on NESTs site

Proprietary systems: Proprietary systems use a serial communications protocol to communicate between the system and the thermostat. Nest thermostats can’t communicate with serial protocols, though some proprietary systems can be re-wired by a professional installer with standard HVAC wires so they can work with a Nest thermostat.

I do not have a rheem furnace but I have an EcoNet water heater. Here is my DH. I am sure It could be adapted to work with the furnace.

hello, i have a brand new for 2018 Ruud/Rheem…
RUUD UETST700SYS thermostat. no one can tell me anything about it. currently it is hooked to a new ECONET enabled a/c only central unit. i have a Buderus boiler. question is… can the boiler be hooked to the thermostat and how should it be wired.

the thermostat also activates the a/c unit every morning for 30 seconds and then shuts off.
is this normal, is it doing some kind of diagnostic thing? it does this in the on and off position. there is no scheduling programed.

i have called ruud they have no tech support for this. the lady there told me they don’t even manufacture their own thermostats. she said they are usually WhiteRodgers.
everyone else i have called just reads product spec sheet off internet
thermostat help line is for wifi only
thanks for any insight into this!

Hey there! I am a rather unique add to this thread. For 15 years, I was an IT guy - have done everything from PC to full on enterprise in that time. My primary focus was infrastructure, both in terms of networking and back-end compute. To say I understand systems would be an understatement. I now work for a buddy of mine who runs a very successful HVAC company. Our primary brand is RUUD and we only install RUUD with ECONET. RUDD/RHEEM are the same as far as ECONET is concerned, same company – markets and marketing determine what brand a contractor can sell.

ECONET allows the contractor to shave about two hours off an install because, when equipped with two simple ohm resistor type temp sensors (one outside, one inside above the A-COIL), automatically sets temperature up-flow and fan-speed. It also allows us to give you similar (I think better) control of your HVAC system without having to run additional thermostat wire. For example, we install NEST with our TRANE systems – that requires a ten wire bundle to do everything that ECONET does in four, thanks to…

ECONET works on serial communication (E1 & E2). R and C are power to the unit (24V + -). The ECONET stat allows control of: humidity (both de-humdification and humidification), variable fan speed, diagnostic controls, condenser control, when to fire stage one heat/cool, stage two heat/cool, etc.

NEST, for example, does give you a lot of data and API, but simply turns on or off 24V controls to engage: fan, heat, cool, humidification, etc. but cannot “think about” what it’s doing, and requires a pair of 24v contacts per action item. So, if you have a 2-stage furnace, 2-stage a/c unit, humidifier, we have to send at least 7 wires to the same place – usually to hell and gone. No reasonable contractor is going to run just 7 wires, we only run 10 when using NEST, so that cost multiples very quickly per foot and time (given that the walls are already built and usually some jackass stapled the wire to the walls).

So, ECONET is very cool, has a lot of data, tells service guys and homeowners how many times the unit has fired, how it’s firing, what fan selections are, what the CFM is, etc. etc. etc. Problem is, they don’t publish information about how to “tap into” these data.

I have not yet had time to look into this, but since it’s a serial bus – RS232, by which E1 and E2 communicate with the furnace, interpreting those data should be easy; just have not had time to focus on that.

As a dealer, and not a small one, getting anything out of RUUD on ECONET is like pulling teeth. Back in my IT days, I’d call this security by obscurity, so my guess is there is ZERO security on the E1/E2 data bus. For instance, recentally in the latest platform (xxx700), there is a problem with the humidity sensor being off and the filter change software calculation being wrong. RUUD/RHEEM admidts humidity issues (I was the first dealer to report) and they have yet to address the second issue. MUM is the word until, whopps, there is a whitepaper.

As for who makes the thing, it’s not RUUD/RHEEM. Who, I don’t really know. The industry as a whole relies on White Rodgers (EMERSON) or Honeywell. My guess, one of those two.

To the question here about controlling a boiler, ECONET will not control a boiler and air handler/A/C. It only will control RHEEM/RUUD equipment. You’re going to have to have two stats to control both items, one for RHEEM/RUUD equipment and one for your boiler. But trust me, it’s worth it. The ECONET outsmarts us mortals about fan speed, condenser speed and how best to make your environment comfortable. Trust me, I’ve lived with ECOBEE, NEST, SENSI and a basic on/off with RUUD/RHEEM equipment and it’s rubbish in comfort by comparison.

Hope this helps in some regard. If you do have specific questions, would like me to look into something, etc. I can be reached at jeremy@brubakershowroom.com.

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I wonder if any one opened econet thermostat to see if it accepts 24v inputs. Any type of interface to legacy controls

Rheem Econet connection type between the air handler, AC condenser and thermostat is RS485. RS485 is serial communications only needing 2 wires, one for RX (receive) and one for TX (transmit) the other 2 wires are power and ground. RS485 allows for having more then a single device connected to these wires. Every device on the wire has the ability to see all of the data. This makes it easy ish to reverse engineer.

Rheem was one of the companies that was involved in the ClimateTalk protocol development. This protocol was an attempt to make a universally accepted communications between the various devices. So one would be able to use a Trane thermostat on a Rheem Furnace if they wanted to. This all fell apart many moons ago. There were 2 companies who actually released units that used this protocol. Emerson was one of them. and Rheem was the other. Rheem’s name for it was ComfortControl2. This was not around all that long before Rheem changed to EcoNet. I am going to tell you that Rheem did not reinvent the wheel and create a whole new protocol. I am sure they have made some changes and added some kind of an authentication so that only Rheem devices would be able to communicate with one another. Rheem does sell an EcoNet to ComfortControl2 interface. It is a really small device and the cost is pretty low. This tells you that this device doesn’t do a whole lot. Probably only handles the handshaking parts. I do not believe that Rheem would have come up with some kind of a crazy authentication routine. You probably only need to authenticate if you are wanting to control. If wanting to only read states I do not think you would have to authenticate.

I would start with the ClimateTalk protocol I will almost bet that the EcoNet protocol is largely identical to it. You should be able to purchase an ESP32 development board for 10.00USD along with a MAX RS485 interface for < 10.00USD wire the thing up to the same RX and TX lines and log the data when you perform operations from the thermostat. use a volt meter to locate the RX and TX lines. You will see them pulsing in the -7v to +12v range.

The ESP32 is capable of running Python and I believe there is a library available for it that will allow the basic communications to take place.

RS485 serial spec: physical (electrical) specification between the devices. This would be what Ethernet is in a network

Modbus protocol: logical connection specification specification, this would be TCP/IP in a network

ClimateTalk protocol: specification for the data being sent/received. this would be HTTP for a network.

I personally have 3 Rheem Furnaces that use the ComfortControl2 protocol. I will be writing a control interface in Python, I just ordered the MAX 485. so as soon as that comes in I will begin working on it.

I know nothing about SmartThings but perhaps someone would be able to port the code if needed.

I’d be happy to put a protocol analyzer on the RS485 bus if anyone’s still interested.

Hi Kevin,

Just wondering if you have made any progress on the control interface to the EcoNet protocol (or ComfortControl2 protocol?
I have air handler and a heat pump, both EcoNet enabled and would like to try to integrate them in to the OpenHab.

Thanks in advance.

Hi Bill,
I would be interested to see what is going on on the EcoNet bus, if you have time and resources.

FYI - Rheem switched to MQTT protocol. There are new drivers on Hubitat.

Not sure if Smart things supports MQTT protocol.

I am not using smartthings anymore but I still follow the forum due to similarities to Hubitat.

My understanding is that it (MQTT) applies to their water heaters only.
Or did they change it for their heating and cooling products?

I have one of the older Rheem EcoNet water heaters. A good 5 years old. Does this fall under the above posts?

I tried the current available SmartApp but when I try to connect to the Rheem website with the username/password, it doesn’t work. The code is pretty old - 4 years as I recall.

Any chance someone has come up with anything new for this or does it fall into the discussion above? Just thought I’d check/make sure. I still have one.