Thermostat Options for EWC-ST Series Control Panels

[wjam]

Are there any newer programmable Thermostats certified for the ST-2C zone controller? I see the list of Thermostats that was given dates back from 2010. I would like a more modern looking Thermo with the programmable features.

I have a EWC-ST-2D panel with conventional gas forced hot air system with AC, no heat pump. I'm using 5-2 programmable Honeywell RTHL2310B1008 which has separate O and B terminals (available from Lowes for $24.98) as the Zone 1 t-stat and an old round mercury t-stat for zone 2. Seems to work fine for heating and cooling. Either t-stat kicks on and turns off the heat or AC and duct motors direct flow to zone 1 or 2 accordingly. Will probably also swap out the mercury t-stat for a second RTHL2310B1008 for zone 2.

[BAB]

I have the EWC-ST-2C controller and just took out the old mercury t-stat. I was planning on installing the Filtrete/3M 3M-30 but not quite as simple as I thought. My new t-stat has separate O and B terminals. However, reading through the tech bulletin for the ST-2E it appears as if the separate Rh and Rc terminals would be more appropriate for these connections, no? If I did that, then I would have nowhere to put the current "R" wire.

I have a gas furnace and running a 6 lead wire (B,O,Y,W,R,G) and the 3M-30 has terminals for C, B, O, W, W2, Y, Y2, Rh, Rc, G, A.

Any help you can provide would be greatly appreciated.

[Pcyrana]

You do not need to use the RC and RH to connect to the O and B terminals.
What you are probably looking at is a diagram that shows a thermostat that uses RC/O and RH/B terminals.
For your thermostat you will connect O to to, B to B and R to either the RC or the RH.
If you have any more questions please let me know.

[rtheriault]

I have a EWC-ST-2E controller with two zones, and a conventional gas furnace. I am running into the problem of finding modern t-stats for my zones that support B and O connections.

After reading posts from forums on other websites, there was a suggestion to ignore the B and O connections and just use the G, W, Y, R wires. The thought behind that suggestion is the t-stat would be able to control whether or not to use heat or cool. The t-stat I'm looking to purchase has both a manual switch as well as an auto sensor to control heat vs cool.

After reading through this forum topic, it is very clear that I need to either purchase MCS-DXB or find a t-stat that can support both B and O connections. Can someone please explain to me why I wouldn't be able to use the features of my t-stat to control heat and cool? Do the B and O connections provide additional functionality that I'm not aware of?

Thanks,

Rich

[Pcyrana]

The zone panel that you have is what is known as a "master slave" zone panel.
The Zone 1 or "Master" thermostat decides whether the zones will be able to run in heating or cooling based on the position of the zone one thermostats system switch.
The zone one thermostat will output voltage on either the O or B terminal to allow the zones to run in cooling or heat.
If you do not have O and B terminals on your zone one thermostat then yes you will need to use the MCS-DXB.

[CoaSal]

I have two EWC-ST-2C Control panels - one for each floor of the house. These control panels service two separate blowers (oil heat and AC units). Each floor and control panel has two thermostats currently connected, which are outdated.

I would prefer to change all four thermostats to programmable thermos that can be programmed separately for each day of the week.

I've reviewed the list of recommended thermos on this thread, but at best I've only noted a 5+2 programmable thermo. Any suggestions without changing out the control panels?

Your advice is much appreciated.
Dave

[Erik W.]

Dave,

You can use a thermostat with a 5+2 program period, just program your weekends for the same temperature as during the week and you should be all set.

Erik

[CoaSal]

Thanks Erik.

What if i want to program differently for more then a 5+2 allows?

My family is home at different times throughout the week so i would prefer the ability to program monday and tuesday different than wednesday and thursday, etc.

In my prior home i was able to do this by using a 7 day programmable thermo.

But i didnt have this control panel in my last house.

Any suggestions for a fully programmable thermo that is compatible?

[Erik W.]

You can set different temperatures for each day, and different temperatures can be set for throughout that day to accommodate for when the house is occupied and unoccupied. The programming is more versatile than just a single set temperature for each day of the week.

Erik

[CoaSal]

Thanks. I apologize for returning to you, as i appreciate your advice but i dont think I have properly stated my question.

I may be wrong, but my recollection with a 5+2 programmable thermo is that i have the option to set one set of temp settings for 5 consecutive days (ie different temps throughout a day, but it would be repeated for 5 days) and another set of temp settings for 2 days.

But lets say i wanted to have monday at low temp for most of the day, tuesday only for the morning at low temps and watmer in the afternoon, wednesday like monday; and different still for the other 4 days in the week. In my last house i could only accomplish this with a fully programmable thermo

This is sometime referred to as a 7-day programmable as it allows seperate programming for each day.

Are you aware of any 7-day fully programmable thermostat that is compatable with EWC-ST-2C control panel.

Thanks again

Dave