I have a new install of a 2 Stage Goodman communicating 16 Seer Heat Pump. GSZC160601 s/n 1807265*** Rev CA. and a Goodman AVPTC61D14 variable speed Air Handler s/n 1902196*** Rev AC with HKSC20DB Rev CA 20KW Heat Strip.
1) I thought the "Communicating" meant a 2 wire connection between the air handler and condenser and using a standard Honeywell VisionPro 8000 thermostat (TH8321R1001) 3 Heat/2 Cool HP. The 2 wire communicating red and green lights indicated the communicating link was working, but the Condenser wouldn't start.
2) Had to use the legacy connections for the system to work.

Q1 The Heat Pump is 2 Stage. Does that use 2Heat and 2Cool ?
Q2 The Elec Heat is 2 stage. Does that require another 2Heat. I guess the thermostat would work with only 3 Heat, but should it have 4 Heat to work properly? (I found only a few 4 heat / 2 cool thermostats). It would be nice to find a wiring diagram of this configuration.

 

The communicating interface is likely 4 wires: 2 for signaling ( probably using the RS423 standard), 2 for 24V power to the defrost control board - if so, there'll be a 4pin connector on the control board(s).
It's probably worth the search time to find the installation manuals for your system where the details of the Heating / cooling controls would be described - and this really should be examined before choosing a thermostat.

 

Thanks for the reply, dsomerv

The Two-Wire Outdoor diagram is not possible since there is no mating connector for pins1 and 2 on the air handler. The System Wiring for legacy controls is now working, but
The condenser manual says: The ComfortNet system is a system that includes a ComfortNet compatible air handler and heat pump. Any other system configurations are considered invalid and must be connected as a legacy system.

The air handler manual says: The ComfortNet system is a system that includes a ComfortNet compatible air handlerand heat pump with a CTK0* thermostat. Any other system configurations are considered invalid and must be connected as a legacy system.

IMHO Goodman is in the process of converting from their old ComfortNet systems that used a $500 communicating thermostat to their new systems that are called ComfortBridge that make a full communicating system and use any standard thermostat.

I suspect that I received (April 2019) one of the old systems and the air handler only works in the legacy mode or with a Goodman CTK04 thermostat!!!!! Neither Goodman or the distributor want to own up to supplying mis-matched equipment.

In addition the installer replaced a defective VisionPro 8000 with a HoneywellT6PRO (TH622OU) which I think is only a 2 Heat 1 Cool which probably uses only the second stage cool. I have no idea how the heat during defrost or two stage electric heat is handled.

This is why I hope for a Thermostat recommendation.

 

Based on the System Wiring for legacy controls shown in the last post, believe I need a 4 Heat / 2 Cool Thermostat. I will post this information in the Thermostat forum to find the best thermostat fit.

 

The Honeywell Prestige IAQ will support 4 stages of heat and 3 stages of cooling.

https://www.alpinehomeair.com/relate...structions.pdf

Did you read that part number on the old stat?
I have seen communicating thermostats that look like a regular Honeywell thermostat.
I only needed to reconnect the orange wire nuts at the condenser to make it work again.
It is surprising the amount of " techs" that don't know how to connect two wires with a wire nut.