Which board to upgrade to for Venstar t5800, Nest, etc.

[masseo1]

I just purchased a home and my wife got me a programmable thermostat (venstar t5800).
I went to wire up the thermostat and noticed an issue... no ground wire, and a separate "O" and "B" terminal.
All six wires come off of the EWC-ST-2C and match the corresponding letters on the thermostat for zone 1.

I saw a previous suggestion of upgrading the controller in order to use a Nest thermostat, so I figured the same would go for Venstar.
I'm just not sure if it's a simple "purchase the new NCM 300 and hook up the wires"

My current setup is as follows:

Controller: EWC ST-2C

A/C: lennox
HS29-651-2P
C23-51/65-1

Furnace (Oil Burner): Lennox
023Q5-140/154-2A

Thermostats:
Zone1 - Honeywell T87F with Q539A104 subbase (6 wires)
R ,W ,Y ,B,O,G

Zone2 - Honeywell T87 with standard subbase ( 3 wires)
R,W,Y

I'm ready to buy the NCM 300, so I just need to make sure it will work with my equipment, and will support latest generation of "smart" thermostats.

Thanks for any help.

[Pcyrana]

Sir,
The NCM 300 will work with your equipment, also the new venstar t5800 is compatible with the NCM 300 panel.

Patrick

[masseo1]

Patrick,

Thanks for the reply.
I've looked at the manuals of the 2 control panels ( my existing ST-2 , and the ncm300). Is it fairly straight forward to put the new panel in? It seems I can essentially just swap the wires over 1 for 1.
If its a bit more complex than that, I guess I'll get a qualified HVAC person in to do it.


Mike

[Pcyrana]

Mike,

It is not a "direct swap" between the two boards but it is still fairly simple.
You are going to abandon the "O" and "B" wires from the Zone 1 thermostat terminal block.
They are for use with the master slave technology that is only used in the ST series panels.
Other than that the swap will be wire for wire.
If you have any questions please let me know.

[waleedijaz]

I'm ready to buy the NCM 300, so I just need to make sure it will work with my equipment, and will support latest generation of "smart" thermostats??

[Paul Z.]

A few questions call 1-800-446-3110X490