Thermostat Options for EWC-ST Series Control Panels

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TTJJJJ
Posts: 4
Joined: Mon Oct 31, 2011 2:46 pm

Re: Thermostat Options for EWC-ST Series Control Panels

Post by TTJJJJ »

Have there been any new thermostats coming on the market since Dec 2010 (when this thread started) that work with the 2t-2c zone controller? I am looking for a 7 day progrmmable. I do not know where to buy the EWC brand t-stat around here (48348). What about the honeywell RTH7600D? It have 6-wire apability but the O does not seem to be an option. Would this t-stat work as the zone 1 controller though?
Thanks,
Tim
Pcyrana

Re: Thermostat Options for EWC-ST Series Control Panels

Post by Pcyrana »

Tim,
The White Rodgers 1F95-1271 and 1F97-1277 are two thermostats that are 7 day programmable and will work on the Zone 1 of the ST series panels.
The RTH7600D will not work because it does not have a separate "O" and separate "B" terminal.
TTJJJJ
Posts: 4
Joined: Mon Oct 31, 2011 2:46 pm

Re: Thermostat Options for EWC-ST Series Control Panels

Post by TTJJJJ »

Ah bummer! Thanks fo rthe quick reply Pcyrana.

It stinks because I just went out and bought the Honeywell this AM to try out. I was thinking it would work based on the wiring diagrams of the honeywell vs. the ST controller. The ST controller zone 1 wiring diagrams shows the O terminal as connected to the RC/O so I figured I could connect this to the RC terminal on the T-stat.

Also, on the T-stat diagram it lists the C1 terminal as C1 or X or B, so I figured I could hook up the B to this one.

See the attachment for my proposed wiring diagram? Are you sure this wouldn't work?

Image

Many thanks,

Tim
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Pcyrana

Re: Thermostat Options for EWC-ST Series Control Panels

Post by Pcyrana »

No Sir unfortunately that thermostat will not work for you. The master thermostat requires a separate "O" and separate "B" terminal.
The way you have it wired in that diagram, the "O" will always be energized and the board will never allow a call for heat.
TTJJJJ
Posts: 4
Joined: Mon Oct 31, 2011 2:46 pm

Re: Thermostat Options for EWC-ST Series Control Panels

Post by TTJJJJ »

Alright cool. Thanks for clarifying that.

The more I look into this, and looking at the cost of the thermostats, I'm thinking of upgrading the board to the BMPlus3000. this would let me hook up my 3rd zone (right now 2 of my zones are hooked to the same stat) and would also allow me to get full use out of a 2 stage furnace plus a 2 stage AC unit when it is time to replace them. Also, i can use the cheaper Honeywell 7 day programmable stats.

I just need to make sure my old actuators are compatible with the new board.

Thanks for all the help!

Tim
Pcyrana

Re: Thermostat Options for EWC-ST Series Control Panels

Post by Pcyrana »

EWC's newer model zone panels will work with any of our older model actuators.
KittyHawkDunes
Posts: 1
Joined: Thu Dec 29, 2011 12:21 pm

Re: Thermostat Options for EWC-ST Series Control Panels

Post by KittyHawkDunes »

Along the same line... I have an EWC-ST-2C with two damper valves, heating and A/C. I am looking to wire an RTH6400 series Honeywell Thermostat. The new stat has G, W (O/B), Y, R, and Rc terminals. Can I wire O and B together. No heat pump, just boiler and A/C with air handler.
Pcyrana

Re: Thermostat Options for EWC-ST Series Control Panels

Post by Pcyrana »

No unfortunately that thermostat will not work with the ST series zone Panel. The master thermostat requires a separate "O" and separate "B" terminal. A combined O/B terminal is not suitable.
JBogon
Posts: 2
Joined: Tue Jan 24, 2012 11:48 am

Re: Thermostat Options for EWC-ST Series Control Panels

Post by JBogon »

I thought I read somewhere the thermostat "C" terminal can be used for the "B" wire and then the "O/B" terminal can be used for the "O" wire in Zone 1. Anyone know if this is true?
Pcyrana

Re: Thermostat Options for EWC-ST Series Control Panels

Post by Pcyrana »

This is not true.
The manufacturers GE, York and Trane use the B terminal as a common or "C".
I'm assuming that is what you are referring to.
This is not the same as the separate B terminal required for the ST panels.
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