Honeywell RTH7600D on dual stage heat pump; can't get it happy.


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Old 11-30-14, 06:01 AM
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Honeywell RTH7600D on dual stage heat pump; can't get it happy.

I have an American Standard heat pump system and I have replaced the T-stat with a Honeywell RTH7600D. Of course, I read the manual carefully, but the wires don't match one to one. After many internet searches, the nearest answer I found to my wiring issues is here. I have made the following connections:

Old T-stat ------ Wire color ------ New T-stat
G ----------------- Green ------------- G
O ---------------- Orange -------------O
24V --------------- Red --------------- R (with jumper to Rc)
24V(c) ------------ Black ------------- C
Y1 --------------- Yellow ------------- Y
W1 --------------- White ------------- (not connected)
W2 ---------------- Blue -------------- Aux (with jumper to E)

Of course, I read the part in the manual that said "If your old thermostat had Y1, W1 and W2 wires, stop now and contact a qualified contractor for help." It was 5:30 on a Saturday and it was COLD in my house. I forged ahead until I found the above mentioned thread, so I thought I could sleep warm.

I made the following settings in the Honeywell T-stat:

0170 to 9 - defined as Heat/Cool multiple stages: 2 heat stages (wires on W and W2), 1 cooling stage (wire on Y).
0180 to 1 - defined as Electric Heat: Use this setting if you have an electric heating system (thermostat controls fan operation).
0190 to 0 - defined as Cooling changeover valve: Use this setting if you connected a wire labeled "O" to the O/B terminal (see Wiring Notes).
0240 to 9 - defined as Electric Furnace: Electric heating systems. (Incidentally, there was no heat pump option at this setting and that bothers me.)

So far so good; I flipped the breaker back on and nothing burst into flames. The unit ran, but cycled on/off very frequently (this could have been because it was so cold in the house when I got through). I didn't measure the cycles, but I'd venture the guess that it was 3-5 minutes on and 1-2 off, then repeat.

So I changed 0170 to 7 (Heat pump: heat pump with backup or auxiliary heating.) which is the way I have it wired, right? The fan ran

all.

night.

long.

So this morning, I changed it back to 9 and it's off for the moment. The temperature has stabilized so maybe I'm good to go, but I'm not sure this is right.

My questions:

1) Did I make the wiring change right? Am I correct to omit W1 on the new T-stat or should it be connected somewhere?

2) Am I correct on 0170 at 9 or is 7 more appropriate?

3) Is 0240 right at 9? I don't think so, but it was the most correct answer given the lack of a heat pump option. You can see the other options in the Quick Start Guide here
 
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Old 11-30-14, 07:15 AM
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Welcome to the forum!! I suggest the following:

White wire on Aux
Blue wire on E

0170 to 7
0180 to 1
0190 to 0
0240 to 3 (manual says 9 but 3 is much better to cycle on/off less)
0270 to 3 (same as above)
 
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Old 11-30-14, 10:47 AM
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Thank you very much, firedawgsatx!

I have all that in place now. I removed the jumper, I connected W1 to Aux and moved W2 to E. Wouldn't you know it, it's 70 right now, so of course, the system isn't running. I'll give that a swing and see how it goes.

When I went back through the options just now, I wasn't offered 0240; only 0270. According to the Quick Start Guide, they have the same answers though, so I'm guessing that's not critical. 0270 is now set to 3, per your recommendation. I'm just asking, though; option 3 is listed as:

Hot water or high-efficiency furnace: Hot water system or gas furnace (more than 90% efficiency).

I'm not running hot water or gas; is this a safe setting for my system?

With all that in place, I have one last question. I have 0300 turned on:

Manual/Auto Changeover: Automatic changeover (Heat/Cool/Auto/Off). Automatically turns on Heat or Cool based on room temperature. Note: System maintains minimum 3F difference between heat and cool settings.)

Somewhere in the manual, I read a warning not to use Auto mode if the outside temperature drops below 50F as compressor damage may occur. What's up with that?
 
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Old 11-30-14, 10:59 AM
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When I went back through the options just now, I wasn't offered 0240; only 0270. According to the Quick Start Guide, they have the same answers though, so I'm guessing that's not critical. 0270 is now set to 3, per your recommendation. I'm just asking, though; option 3 is listed as:

Hot water or high-efficiency furnace: Hot water system or gas furnace (more than 90% efficiency).

I'm not running hot water or gas; is this a safe setting for my system?
Some Honeywell thermostats do allow to set function 240 but apparently yours does not. Emergency heat is only used when the heat pump is broken. If you feel 9 is a better setting that is fine.


With all that in place, I have one last question. I have 0300 turned on:

Manual/Auto Changeover: Automatic changeover (Heat/Cool/Auto/Off). Automatically turns on Heat or Cool based on room temperature. Note: System maintains minimum 3F difference between heat and cool settings.)

Somewhere in the manual, I read a warning not to use Auto mode if the outside temperature drops below 50F as compressor damage may occur. What's up with that?
I prefer to do a manual changeover.
 
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Old 11-30-14, 11:24 AM
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Thank you for your assistance. I wasn't questioning your answer at all, just trying to be sure I understand so I can learn from all this. I wouldn't have opted for that on my own as I was looking exclusively for heat pump related settings.

I appreciate your help; thank you,
Belch out.
 
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Old 11-30-14, 11:32 AM
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The reason I suggest setting function 270 to 3 is when it's at 9 the heat will cycle on and off a lot more often if you are ever operating in emergency heat mode.

9 will work and if you find that the electric heat comes on and off way too often to your liking you can easily change it to 3.
 
 

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