[Mackall]

OK so I'm looking for some help as to what I may be doing wrong here. I marked all the wires before I removed the old wall mount. Once I removed the old wall mount I found another wire in the wall that seems to serve no purpose. The wires on the old thermostat were very simple. W_G_R_O_Y... and there was a blue wire that was disconnected in the wall.

So the A/C works fine, the fan kicks on and I hear the compressor going outside as well. However when I turn on the heat it will say 'Heat On', then after a few moments it will change to 'Aux Heat On'. I know that sometimes the Aux Heat will kick on to assist the heat pump but even with a small temp change (2-3 degrees) the Aux Heat goes on and I don't hear the compressor kick on at all outside.

I bought a new Honey Well thermostat that is compatible with my Heat Pump with Aux Heat. I connected all the wires as explained in the diagram but the only spot for the R wire was a spot that was coupled with an RC wire which I did not originally have. Also I am not sure where the mystery blue wire should go. I tried connecting it to the C connection but still no heat pump kick on.

There is also no spot for my W wire. There is a W1 spot which the user manual said W1 or W wire connects here. But I'm just not sure about where I went wrong. Should the compressor even kick on for the heat pump because all I hear is the fan inside the house which signals to me (As the thermostat reads) that it is just the Aux Heat coming on.

Any help would be appreciated.

[hvac1000]

You need to check the reversing valve circuit in the outdoor heat pump to see why it is not changing over from cool to heat.

What is the BRAND and MODEL number of your new thermostat?
What was the BRAND and MODEL of your old thermostat?

[Mackall]

New thermostat is Honeywell rth7400... the onld one is a honeywell also but I don't know the model #. It's got a slider control on top for temp and fan and heating/cooling sliders on the bottom.

New one is programmable and old one is not programmable.

Where is the reversing valve circuit located? In the back of the unit outside?

[hvac1000]

Before you start tearing the outside unit apart make sure your thermostat is wired correctly and that all the SETUP features are properly programed for your system.

Below is a copy of your manual for your new thermostat just in case you lost the original.


http://customer.honeywell.com/techli.../69-1900EF.pdf

[Mackall]

Yea I programmed it using the manual and programmed the correct selections. I'm just thinking could some wires be missing? Am I connecting them correctly? Page 13 in the manual has so many wires shown (this is to cover all scenarios I know) but I only had 5 wires connected and the blue one in the wall makes 6. So confused, maybe I will try to call Honeywell support. The thermostat wizard online did nothing for me.

If I posted a pic of the old wiring and the new wiring would that help?

[hvac1000]

yea I programmed it using the manual and programmed the correct selections. I'm just thinking could some wires be missing? am I connecting them correctly? Page 13 in the manual has so many wires shown (this is to cover all scenarios I know) but I only had 5 wires connected and the blue one in the wall makes 6. So confused, maybe I will try to call Honeywell support. The thermostat wizard online did nothing for me.

If I posted a pic of the old wiring and the new wiring would that help?

Post the pictures if you wish

[Mackall]

Here's a pic I took of my wiring. Again all settings in the programmable thermostat are correct. Still I do not hear the heat pump kick on outside even after some time. It just stays on Aux Heat. I've connected the blue wire that was in the wall to the C port and the W wire to the AUX port following the manuals suggestions. R is connected to RC and jumpered to R. O (as marked from the original setup) is actually the gray wire. Green and Yellow are hooked to G and Y respectively (as marked from orig).

HAHA and I am following the Heat pump connections also, I just can't figure it out.

[Mackall]

Oh yea and I found this on another site. It helps to shed light on some of the colors and connections. Does this wiring scheme seem correct. I don't have all those wires but the ones I do are connected as illustrated.

[Mackall]

Well I followed the diagram above and I think my problem was I had the red wire connected to R not RC. So I followed the diagram and connected to RC and jumpered to R. All of my colors correspond to the diagram. Except o/b m wire was gray.

So if anyone else is having the same poblem I hope reading this post can help you. HVAC 1000 was helpful and so was that diagram.

[hvac1000]

Glad you got it going. I saw your picture but I could not tell how it was wired exactly. At my age I wear reading glasses but I am going to have to get a new pair soon.

[mikenguyen]

I check all wire correct ,but when turn on the heat contactor is not snap

[monterrosos]

I'm looking for help with something similar, I have a thermostat with R (red wire), G (green wire) y1 (Yellow wire) w2 (white wire), w1/O/B (white wire), y2 (light green wire) and C (blue wire).

My new thermostat has B, O, G, Y, W/Aux, n/u, R, RC

Where do I put the y2 wire? I placed Green on G, Yellow on Y, White on W/Aux, Blue on n/u, red on R (kept jumper to RC), white from W2 on O. Where does the Light Green Y2 Wire go?

I know it is for 2nd stage Cooling do I need a different Thermostat?

[Grady White]

Your old thermostat was two stage cooling & three stage heat. Your new one is one stage cooling & two stage heat.