Communication Issues
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Communication
While the EcoNet bus is very easy to wire, occasional communication issues have been reported and more often than not, its a simple mis-wire between equipment. The EcoNet bus consists of 4 wires: 24V, Common, E1 and E2. If when starting the system up, you don't see, for instance, the outdoor unit you will have to determine a few things first.
1. Is the outdoor unit a communicating outdoor unit?
2. Is the outdoor unit wired using the same colors as it has at the thermostat and the air handler or furnace?
3. Are any devices breaking any of these such as float switches or utility connections? Hint: They should not, we have auxiliary and utility inputs for those.
4. For inverter units with a UODC or VSODU, make sure you are NOT connected to RT outside. Red goes to R.
5. For the RD17 Universal Heat Pump only E1 and E2 are connected. It has it's own transformer providing low voltage to the outdoor unit. Existing Low voltage wires including R and C are to be capped off. They DO NOT connect to the din rail.
Those may be simplistic, but double check. If you have blue going to E1 at the thermostat and E1 at the furnace, did you make sure blue is going to E1 at the outdoor unit? One simple test you can do is to remove the wires and flip E1 and E2 to make sure there are no hidden wire nuts crossing wires between the outdoor unit and the indoor unit.
Another simple check would be to remove E1 and E2 and measure DC voltage from each to C. If you measure roughly 3 volts DC to Common from one of the wires, then you are holding the E1 Wire. If you read just over 0-0.2VDC to common, you are holding the E2 Wire. You can measure from the empty E1 terminal to C and you should see about 3 Volts DC. E2 to Common will be closer to 0-0.2 volts DC
These measurements are to be done with E1 and E2 disconnected from the outdoor unit but R and C must remain connected. Make sure of course you don't have R and C swapped too.
If you aren't getting voltage, you will have to make sure you don't have a broken connection between indoor and out somewhere between.
Attempting to install a transformer in the outdoor unit will not work. The C and E1 are closely related and if the transformer is not phased properly, and even if it is, the relationship between E1 and your supplied common may be no good. You must run 4 wires from inside to the outdoor unit. Make sure you are not inducing voltage on communicating lines by running them inside or along side, line voltage wires.
Also, its always best to run a daisy chain wiring scheme. That is to say, you should not build a star with one device being the hub. Really there should be no more than 2 wires under any E1/E2 terminal or wire nut. One in and one out.
Thermostat-----ID------OD
R----------R---------R
C----------C---------C
E1---------E1--------E1
E2---------E2--------E2
