Trying to install thermostat - unable to locate type c in control board

[niroshthanga]

Hi,
I am trying to install a smart thermostat that requires common wire (type c).
Can i get some assistance in locating the common wire in the control board?

Attaching picture of the EWC control board and model
Appreciate your insights

[Steven W.]

Smart thermostat's will not work with this zone board. You are going to need to update the board to a NCM 300.

[niroshthanga]

Thanks for prompt response.
I do have 4 thermostat with the control board i have currently, NCM 300 would work correct?
Reason: NCM 300 has limit of 3 zones and if i have 4 zones, do i need to upgrade to something else?
Or number of thermostat is irrelevant.

Please advise so that i can go ahead with the purchase.

[Steven W.]

You will need to upgrade the NCM to the Bmplus 5000 that will give you 5 zones

[niroshthanga]

Thanks!