# Proprietary Info and Communicating Thermostats



## Yuri Z (Oct 27, 2020)

I do mostly Lennox units now and am finding that every brand now has their own unique Communicating thermostats and codes and diagnostics.

Do other techs find that they are primarily working on their own brand like Carrier, Lennox etc as trying to get tech info for a Modulating furnace like a Lennox SLP and tech manuals is impossible unless you are a dealer? 

Is the trade getting to the point where you take your car to the GM dealer only if it is a GM as Ford does not have the diagnostic info and it is easier and better to take it to the dealer.


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## beenthere (May 30, 2009)

It is hard sometimes to get the tech support you need on communicating units. But haven't had too much serious trouble.


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## Sm_raudales (Jan 18, 2021)

Communicating HVAC:

Used with some two-stage and all variable-capacity HVAC systems
Require just four wires – two power wires for heating and cooling and two for communication between components
When communicating equipment is installed, the thermostat searches for the components in similar fashion to how your smartphone searches for a Bluetooth speaker you want it to pair with
Once the thermostat and components are paired, the components communicate to the thermostat what their capabilities are in terms of heating and cooling capacity and, for blower motors, how much air they can move through the system, which allows the thermostat to set up optimal performance
Each component has an electronic address, so the thermostat knows where the data is coming from and can send data back to that component to control its operation
A computerized serial network allows each component to send ongoing performance data that refines performance
Indoor and outdoor sensors allow the thermostat control to determine and communicate exactly how much heating or cooling, dehumidification or humidification and air flow are required to keep the home optimally comfortable


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