EWC Controls Forum

Hi everyone. First time posting on this forum. I was trying to find a programmable thermostat for my EWC-ST-2E with three zones. After a lot of research on this forum, I found out that the Honeywell TH4110D-1007 was compatible with my system. So I went ahead and bought three. The setup seems to work with one caveat... The heat turns on and off whenever it wants even if the thermostats are not calling for heat. Even when the main thermostat is off (the zone 1 thermostat), the heat will cycle on and off. So my guess is that my wiring is incorrect since everything was working fine before I changed the thermostats. So here is how I wired the system.

Zone 1 --> Thermostat
W --> W (White)
Y --> Y (Yellow)
R1 --> RC with a jumper to R (Red)
O --> O (Brown)
B --> B (Blue)
G --> G (Green)

Zone 2 & 3 --> Thermostats
W --> W (White)
Y --> Y (Yellow)
R --> RC with a jumper to R (Red)

Three things to note...
-For zones 2 & 3, a blue wire was used for Y. I am assuming the HVAC guy probably just ran out of yellow wire. So I connected the blue wire to the "Y" terminal on the thermostat since there was no yellow wire.
-I was not sure how to connect the red wire onto the thermostat. I tried just using the "R" terminal without a jumper, but then air conditioning unit would not come on. The only way both the AC and heat would work is if there was a jumper of R and RC.
-Finally, I left all the default settings on the thermostat including the Fan Switch set to "Gas and Oil" for all three thermostats.

I have oil heat by the way in case that matters.

Any help would be greatly appreciated. I want to make sure I don't blow up my furnace with the constant turning on and off..

Thanks,
Ed

Just as an update. The thermostats seem to call for heat without any issues. What's odd is that the heat will also come on when the thermostats are not calling for heat. However, when this happens, the fans only stay on for about 30 seconds before shutting off. It seems to happen about every 5 minutes.

But at least when the thermostats do call for heat, everything is working fine. So far we have managed to stay warm, but I would appreciate any help since I am sure it's just a matter of time before by furnace gives out with the constant on and off.

Ed

I could see this happening if your furnace is a forced hot water system. My previous residence had an oil furnace that needed to maintain a minimum core temperature when otherwise not in use, so it could supply heat immediately upon demand.

Yours sounds like a forced-air duct system, yes? And the fan turns on for 30 seconds every 5 minutes? Maybe you have a faulty thermostat? Is the fan switch on "auto? If when this happens, you use a voltmeter to measure AC voltage, what do you get for voltage between C and W (zone 1)? And for the 30 seconds the fan is on, what do you get between C and G?

Thanks for the reply. I do not have a voltometer, so I will have to stop by home depot to get one. However, I am assuming that based on your reply, you would agree that the way I wired the thermostat is not the issue... correct?

In terms of your question on whether my furnace is a forced hot water system, how would I be able to tell that? I just moved to the home not to long ago, and oil heating is all new to me. I know it is forced air, but don't know about the forced hot water system. There is a tube that's about 8-10 inches thick that runs from the hot water heater to the furnace. It looks like an aluminum vent tube. The model of the furnace is a Hallmark LBD115.
I will say that the heat that comes out from the furnace is instantly warm. So it does not take long at all to heat up my home.

Once I get the voltometer, I will post my results.

Thanks for your help.

Edgar

Edgar,

If your unit is still running without a demand from any of the thermostats;
Try disconnecting the "R" wire from the system terminal block of the ST-3E zone panel in the lower left hand corner.
With the "R" wire disconnected, does the fan continue to turn on and off every 5 minutes?
Note: After you try this test you will need to re-connect the "R" wire to the Zone Panel in order for the heat to turn on when the thermostat calls.

_________________
Patrick Cyrana
Pcyrana@ewccontrols.com
1-800-446-3110

Just got my voltmeter today and here are the results:

When off thermostat is turned off:
W: 26.2 V
Y: 0 V
G: 19.1 V
O: 19.2 V
R:
B: 0

When thermostat is On and calling for heat:
W: 26.2 V
Y: 0 V
G: 18.5 V
O: 18.5 V
R:
B: 26.2 V

When thermostat is On and not calling for heat (but fan running):
W: 26.6 V
Y: 0 V
G: 19.0 V
O: 18.8 V
R:
B: 0.0 V

Please let me know if these voltages look correct. As for Pcyrana suggestion, I will try it this weekend. I've been getting home late so I haven't had time to hit the basement.

Thanks everyone for your help.

Ed

Ed,

Based on those voltages you have read it looks like there is something wrong that is causing your heat to turn on and off intermittently.
It seems like there could be an issue in the field wiring.
If you can, please give me a call when you get a chance. 1-800-446-3110
If you do not get time to get back to me before the weekend, here is something else you can look into.
The Honeywell TH4110D thermostat has the following terminals...

R
Rc
C
W
O
B
Y
G

I would like for you to tell me what COLOR wires you have connected to each of these terminals on the zone 1 thermostat.

Then tell me what COLOR wires you have attached to the the zone 1 thermostat terminal block on the zone panel. Terminals below...

C
W
Y
R

R1
O
B
G

That should help a lot with the troubleshooting process.

_________________
Patrick Cyrana
Pcyrana@ewccontrols.com
1-800-446-3110

Pcyrana,

Thanks for the reply. I will try to call Monday if I get some time during work. In the meantime, here is the information you requested:

COLOR wires attached to the Honeywell TH4110D thermostat terminals:

R: "red"
Rc: "empty" (However, there is a jumper that connects R to Rc)
C: "empty"
W: "white"
O: "brown"
B: "blue"
Y: "yellow"
G: "green"


COLOR wires attached to the the zone 1 thermostat terminal block on the zone panel:

C: "empty"
W: "white"
Y: "yellow"
R: "empty"

R1: "red"
O: "brown"
B: "blue"
G: "green"


***Note the blue wire that is being used in zones 2 & 3 instead of a yellow wire.***

Thanks for your help.

Ed

I haven't had a chance to call. I've been getting home around 8pm every night. Let me know if my pictures help though.

Thanks for everything.

Ed

The pictures do help.
All of the wiring looks to be correct.
The fact that you have voltage on W when the thermostat is OFF leads me to believe that you might have a short in the wiring.
To test for a short you can disconnect the W wire from the zone panel and from the thermostat.
With it disconnected on both ends, check for continuity between that wire and all of the other wires in the same jacket.
Also check for continuity between the W wire and earth ground.

_________________
Patrick Cyrana
Pcyrana@ewccontrols.com
1-800-446-3110