Thermostat wiring

Old 02-25-03, 04:14 PM
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Thermostat wiring

Well, cold has visited the Dallas area, and my electric heat pump doesn't seem to be working quite right. I had a service call on it a few weeks ago, and the rep said it looks good except that the defrost board on the outside unit doesn't appear to be working properly.

Today, I noticed that when I put the switch of the thermostat into "emergency heat" mode, I get cold air through the ducts. However, the service rep found that when he moved the thermostat so that both mercury bulbs are on, a clamp ammeter showed that the heating coils were drawing current. (I don't believe he tested the 'emergency heat' switch.)

I was wondering: can a wiring problem account for both the lack of heat while the thermostat is in "emergency heat" mode, and for the lack of function of the thermostat board?

I don't have a clamp ammeter to test current draw of the heat coils myself at the moment.

Here's the current wiring arrangement:

The thermostat is a Janitrol model, bimetallic strip coil, with one mercury bulb to turn the heat pump on and a second to kick in the supplemental heat from the heating coils. Wiring is terminals Y, G, R, O, W2, and C to yellow, green, red, orange, white, and light blue, respectively. Terminal E on the thermostat has no connection.

At the air handler, the red, green, blue, and white wires are connected to the same-color wire on the furnace. The brown wire from the furnace has no connection. The orange and yellow wires from the thermostat have no connection to the air handler.

This kinda puzzles me. The sticker on the air handler says taht "brown and white wires are used with heat kits only." Having one connected and one not connected doesn't seem appropriate. Are the supplemental heating coils the "heat kit" that the sticker refers to?

Going out to the compressor outside, the yellow, red, orange, white, and lt. blue wires go outside. The green wire from the thermostat doesn't go outside. I haven't taken the cover off the compressor to determine where those wires are connected to.

The system works great in air conditioning mode, but I've had lingering disappointment with heating mode. Many times I've noticed the blower blowing room-temperature air.

Should that brown wire from the furnace be connected? If so, to what? What about the E terminal of the thermostat?

The air handler is a Goodman Mfg. model AR36-1, and the heating coils are model HKR-10. The outdoor compressor is, I believe, a Janitrol unit.

Does anyone see any problems with this wiring arrangement?
Old 02-25-03, 06:46 PM
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a jumper from e to w2. this will energize the strips when emergency heat is called for. orange and yellow go straight outside, energizing the reversing valve and contactor respectively. look to see where the brown wire goes, it may energize another bank of strips.
Old 02-28-03, 01:08 PM
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If the brown wire goes to either the strips or a black relay near the strips it is probably the control wire for the strips. After you add your jumper wire, connect the brown wire with the 3 already white wires. Make sure you turn the power off first, and also you may need a larger wire nut for the 4 instead of 3 wires connection.

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