Thermostatic Controls - Honeywell to Hunter thermostat conversion wiring

I currently have an old Honeywell manual thermostat that I want to replace with a Hunter Digital Programable thermostat (Model 44250A). The thermostat controls an oil burner furnace and an electric AC unit.

The Honeywell is wired as follows:

There is a five wire bundle with a red, white, yellow, blue, and green wires. They are connected as such:

red wire - R
white wire - W
yellow wire - Y
blue wire - B
green wire - G

There is an additional yellow wire connected to the O terminal.

The new Hunter thermostat has five terminals:
RC, RH, G, W, Y

Based on how my old thermostat is wired, what wires should go where on the new thermostat?

Thanks in advance.

What's the model # on the Honeywell T-stat?

The "B" is telling me you have a heat pump, or hot water heat, or zoned system.

Do you have either of those above?

Don't wire anything till we figure out what you got there.

I don't have a heat pump or hot water heat. It is a oil burned forced hot air furnace, with a seperate air conditioning system. There are two zones, downstairs and upstairs. I was planning on only replacing the downstairs t-stat which controls the heat / cool and fan (on / auto). I don't have the Honeywell t-stat models numbers in front of me, but I will get them for you along with the make/model of the furnace.

Thanks

Bingo.. Zoned system.


The Hunter will not work for you if you have a zoned system. You need to either use a Honeywell or RiteTemp thermostats.

While you are getting back to me with the model # on the t-stat, give me the model on the zone control system.

Thanks,

The Hunter t-stat was purchased about 8 years ago for a previous (single zone) home that I owned, and I never installed it. I'll get you the model numbers for the existing t-stats and the zone control, and maybe you can help me decide what new t-stat to buy and how to properly wire.

Are you planning on replacing both stats on your zone or just one?

I posted this question last week when I wanted to replace my Honeywell manual dial type t-stat with a Hunter digital programmable t-stat. There are two zones in my house, downstairs and upstairs and I found out that the Hunter t-stat can not be used on a multi zoned heating / cooling system.

Over the weekend I purchased a RiteTemp t-stat (model # 6022) at Home Depot which supposedly can be used on multi zoned systems. Before I install I thought I would re-post my particulars to make sure it gets wired properly. Here is the rundown of the equipment I have. All of which dates back to around 1993 when the house was built.

1. Hallmark Warm Air Furnace – Model # LBD115 (oil burned system with two zones, downstairs and upstairs)
2. Central Air Conditioning System (not sure what brand or model #)
3. Ultra Zone Control Panel – Model EWC-ST-3C
4. Existing downstairs t-stat – Honeywell manual dial type t-stat with controls for Heat / Off / Cool and Fan On / Fan Auto. I’m not sure of the model #. These are the only numbers I could find on the t-stat – LR1620…. T87F 2873 3…. 9446… Q539A10143.
5. Existing upstairs t-stat – Honeywell manual dial type t-stat with no controls. Model #? – LR1620… T87F 1859 3… 9445.
6. Also there is a built in Humidifier with a Humidistat that no longer works. The reason I mention it is because it comes into play with the way the t-stats are wired.

Existing Wiring:

Zone Control Panel:
Zone 1 (downstairs)
C terminal – heavier gauge white wire (does not go to t-stat)
W terminal – white and red wire (red wire is labeled as humidistat)
Y terminal – yellow wire
R terminal – blank
R1 terminal – red wire
O terminal – yellow wire (labeled as humidistat)
B terminal – blue wire
G terminal – green wire

Zone 2 (upstairs)
C terminal – blank
W terminal – blue wire
Y terminal – white wire
R terminal – red wire

Downstairs t-stat (zone 1):
R terminal – red wire
W terminal – white wire
Y terminal – yellow wire
G terminal – green wire
B terminal – blue wire
O terminal – yellow wire (not labeled, but I assume this is the same yellow wire from the zone control panel - O terminal, that was labeled humidistat).

Upstairs t-stat (zone 2):
R terminal – red wire
Y terminal – white wire
W terminal – blue wire

New RiteTemp t-stat:
Has the following terminals C-B-O-W2-W-Y-Y2-RH-RC-G-A

Based on the information I have provided how should the new RiteTemp t-stat be wired?

Finally, can I use the Hunter t-stat (model # 44250A) with RC-RH-G-W-Y terminal in the upstairs zone 2? If so, how should it be wired?

6. Also there is a built in Humidifier with a Humidistat that no longer works.
Do you plan on fixing this or replacing it?


O terminal – yellow wire (labeled as humidistat)
is there only one wire on this?


W terminal – white and red wire (red wire is labeled as humidistat)
Undo the red wire if you don't plan on using the humidifer


Zone 1 (downstairs)
C terminal – heavier gauge white wire (does not go to t-stat)
Find out where this wire is going to.


Old---------Color-----------New
R terminal – red wire------Rh
W terminal – white wire---W
Y terminal – yellow wire----Y
G terminal – green wire----G
B terminal – blue wire------B
O terminal – yellow wire----O

Then put jumper on 1,2,3,4,7 at the t-stat. Other numbers should have no jumpers on it. (5,6 & 8)




Finally, can I use the Hunter t-stat in the upstairs zone 2?
Yes.

Upstairs t-stat (zone 2):
Old-----------Color-------new
R terminal – red wire-----Rc/Rh (jumper)
Y terminal – white wire---Y
W terminal – blue wire----W

Make sure switch set to "HG"

Do you have an extra wire in the wall for the thermostat?

I finally got around to wiring the new RiteTemp t-stat based on Jay's advise.

I did not wire the yellow wire (O terminal on old t-stat) that was labeled humidistat on the zone control panel (O terminal). I also disconnected it on the zone control panel. I do not plan on using the humidifier.

I also disconnected on the zone control panel: 1)the heavier gauge white wire (C terminal) that I found out went to the humidifier, and 2) the red wire that was on the W terminal. This red wire went to the humidistat. I obviously left the white wire that was also connected to the W terminal on the zone control panel that went to the W terminal on the old t-stat.

On the new t-stat I connected:

red wire to RH terminal
white wire to W terminal
yellow wire to Y terminal
green wire to G terminal
blue wire to B terminal

Jay indicated I should put the jumpers on 1,2,3,4,and 7.

I put the Jumpers on 1, 4 and 7. I left off the jumper on #2 because I want 12 clock, not 24 hour and #3 because I want Fahrenheit not celcious readout.

The new t-stat works fine for the heating system, but when I place the control to cool and lower the temp setting to 10 degrees below the actual temp, the central air does not come on. The blower on the furnace seems to come on, but the condenser outside never comes on.

What should I do now? I suspect it has something to do with the blue wire. Remember, I do not have a heat pump but I have a blue wire that is connected to the B terminal on the zone control panel and the B terminal on the old t-stat.

I did not wire the yellow wire (O terminal on old t-stat) that was labeled humidistat on the zone control panel (O terminal). I also disconnected it on the zone control panel.

but when I place the control to cool and lower the temp setting to 10 degrees below the actual temp, the central air does not come on. The blower on the furnace seems to come on, but the condenser outside never comes on.



O needs to be wired up.. The zone board does not know if the t-stat is calling for cool or not.l

Re hook up the O.