I recently purchased a Honeywell RTH230B thermostat and was all ready to start connecting it up when I found that the connectors appear to be a bit different. Before I mess something up, I wanted to make sure that I was doing the right thing. I have a Lennox Elite Series CB29M-46-1P unit connected up to a Lennox thermostat. The base board in the thermostat is marked with two labels: the one in the lower left indicates
"30V.A.C.1.5A, LR11746, Class 2, 9519"
While the one on the right indicates
"LENNOX, 78H2201, 3AAT89A38A2"
And it has connectors marked as W, B, O, Y, R, G while the wires coming into the thermostat are color coded as white, black, yellow, red, and green.

The wires are currently connected as follows: W is jumpered to Y, the black wire is connected to O, the yellow wire is connected to Y, the red wire is connected to R, the green wire is connected to G, and the white wire is disconnected.

My new thermostat has the following connections: Rh, Rc, W, Y, and G. My first question is whether the thermostat was correctly connected up in the first place. My second is, how should I connect up this new thermostat?

The new t-stat may not be compatible with your system. The "O" terminal suggests that you have a heat pump system - correct? Also, something is fishy about the "Y" to "W" jumper. This would cause the heating AND cooling to always operate simultaneously.

I believe it might have a heat pump, but not sure. Is there an easy way for me to determine whether it does? Is it possible that the Y to W jumper works because there is a switch on the thermostat that requires a manual choice between heating and cooling? NOTE: I purchased this house about 8 months ago and that's how everything was connected. Haven't had to use heat yet (as I live in Florida) but it appears to work.

Also, if this isn't the correct thermostat, what thermostat would you recommend for setting weekly controls (with separate settings for weekends).

KC:

The Y & W jump happens on some mobile home furnaces where the heat/cool mode is selected at the furnace. Yep, unusual configuration.

As KC suggested, it looks as if you need a 1H/1C heat pump thermostat 1H means 1 stage heat and 1C means 1 stage cool.

If it's a heat pump then the outside unit will run in both heating and cooling modes.

Yes, with Y and W jumped, it can work because O/B determines if the stat is heating or cooling.

I don't encounter too many mobile homes, so perhaps this is an arrangement I'm not familiar with. In a conventional application, the "Y" terminal controls outdoor unit operation, the "W" terminal controls auxiliary heating, and the "O" or "B" terminal controls the reversing valve on the heat pump. If the "Y" to "W" jumper was inappropriate in this case, I'm certain you would have noticed poor cooling performance and excessive electric bills by now.

KV:

Your right, but I'll bet that there isn't any aux heat (heat strips) in Florida.

I am getting confused a bit about W, W1 and W2 with respect to heatpumps. It seems as if they want W2 to be aux heat, but that doesn't seem to be the case.

Do you know if a tstat has say w1 and w2, if the stat calls for stage 2, will stage 1 also be on?

I do see what your saying in this case. Aux heat and the heat pump would be on at the same time. Maybe there wasn't another wire and someone cheated. It would make some sense to see if there are heat strips in the unit.

After all, the OP said he's rarely used heat.

Honeywell's Focus Pro series is primarily designed for the homeowner.

The Vision Pro series might be more flexible but is designed for professional installation. Too many configuration parameters.

See: Thermostats - iaqsource.com

Tak a look at some of the instructions and see which one you like.

It might be wise to look and see what terminals are available at the air handler. Post a link to a manual if you can find one. I haven't looked.

Given your comments, I would assume that there probably is a heat pump since the outdoor unit does run in both modes. There are no ports in the installed thermostat for W1 or W2 (just W, B, O, Y, R, G). I seem to recall the home inspector saying something about heat strips, but I don't think he was sure whether they existed or not without taking things apart. In any case, both the cooling and heating modes seem to function properly (though, given the old equipment and apparent ad hoc installation, probably not the most efficiently).

Also I just wanted to note that I actually live in a 2000 sq ft concrete block house, not a mobile home (though 300 sq ft of it doesn't actually get air directed to it since it was originally designed to be a separate garage space).

One lesson I have learned is that I shouldn't buy replacement electrical components without doing some research first. Figured I would've learned that one by now. Thank you for all of your comments. You have both been very helpful.

Quote:

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Originally Posted by KeepItSimpleStupid

It might be wise to look and see what terminals are available at the air handler.

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Wise indeed. Note letter designations of terminals, colors of wires connected to each, and color of any wires that are unused or not connected directly to the unit.

Quote:

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Originally Posted by KeepItSimpleStupid

KV:

Your right, but I'll bet that there isn't any aux heat (heat strips) in florida.

I am getting confused a bit about W, W1 and W2 with respect to heatpumps. It seems as if they want W2 to be aux heat, but that doesn't seem to be the case.

Do you know if a tstat has say w1 and w2, if the stat calls for stage 2, will stage 1 also be on?

I do see what your saying in this case. Aux heat and the heat pump would be on at the same time. Maybe there wasn't another wire and someone cheated. It would make some sense to see if there are heat strips in the unit.

Afterall, the OP said he's rarely used heat.

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There are a few variations in the way multi-stage heat pump thermostats manage the "W" output(s). In the normal heating mode, any "W" output is secondary, or lags behind, the "Y" output. In the emergency mode, "Y" output is eliminated from the staging order. In any combination they are present, numbered "W" outputs will be staged in numeric order. The "E" output (when present) will only be included as an available stage when the emergency mode is selected. "O" and "B" outputs are used to energize the reversing valve circuit in cooling or heating mode, respectively. I hope this may be helpful in some way.

Almost helps. Specific question.

Suppose thermostat calls for stage 2.
(thermostat terminals W1 & W2) or (W & W2)

Will they both be ON in a call for stage 2 heating?

That's where the variations come into play... but usually they are separate stages.