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Installing Honeywell RTH6580WF - Elec BU Heat Question on Heat Pump System

Installing Honeywell RTH6580WF - Elec BU Heat Question on Heat Pump System


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Old 01-20-13, 08:47 PM
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Installing Honeywell RTH6580WF - Elec BU Heat Question on Heat Pump System

Hello.

I am changing out the current old style Janitrol HPT18-60 thermostat wired as shown in this picture:

[ATTACH=CONFIG]8148[/ATTACH]

Wires are Y, G, R, O, C, E, W2.

I am changing to the wifi Honeywell RTH6580WF. The heat pump unit outside is a Goodman.

The swap out seems pretty straightforward, but before I do so, I'd like to try and learn more about the electric heat function.

According to what I am reading, the Y, G, R, C and O wires are straight swaps to the Honeywell Y, G, R, C and O/B spots on the unit according to the bottom row letter designations on the new thermostat (heat pump line vs conventional letter line on the top).

My confusion: I am reading that I must combine the black "E" wire and white "W2" wire together and put them in the Aux/E spot on the Honeywell. What will this do to the electric back-up and/or emergency heat function? I have never ever seen the "emerg heat" light come on, on the old unit. Hooking these two together, will I be using the electric support more often? We do plan to raise and lower settings based on schedules, not by two much, but 2 or 3 degrees (work / home).

Can the time of temp variance the elec heat comes on be adjusted with this unit or should I use the Filtrete 3M-50 unit? I read that is a little more flexible, but the Honeywell has better overall reviews.

Also, on the new unit, there is a jumper connecting R and RC, leave it?

Thanks!
 
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Old 01-21-13, 02:50 PM
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By the way..... is it worth it to upgrade to the touchscreen for $40, other than the always on backlight setting, no buttons and filter change reminder? TIA
 
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Old 01-21-13, 04:56 PM
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What heat strip do you have? How is the control wiring connected to the air handler?

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Around here I wouldn't want more than 10 KW on the Aux/E terminal.

If you have 20 Kw and W1 and W2 terminals in use, you might consider putting the W2 wire from the outdoor unit to the air handler W2 and connect the stat Aux/E to the air handler W1 terminal.
 
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Old 01-21-13, 05:50 PM
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Thanks, not sure what heat strip I have, how do I find out? I have no W1, just a W2. So... I shouldn't combine the E and W2?
 
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Old 01-21-13, 06:26 PM
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You don't have a W1 at the air handler?

You can combine them, but if you have 10KW control by each of them you may see an expensive increase in your electric bill. (10 kw = 10,000 watts, so 10kw x 2 would be 20,000 watts)

I would tape off the E wire and try operating the system for a week of winter.
If you feel comfortable leave it this way, or, open the panel and read the tag on the heat strips before risking an additional hundred dollars on the next light bill.

 
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Old 01-21-13, 06:29 PM
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Ahhh, great, thanks for the pic. I'll try as suggested as well as check the end at the air handler. Thanks!!
 
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Old 01-21-13, 06:57 PM
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Most air handlers do not list the heat strip information on the air handler tag.
The installer should place a sticker with this information on it but many do not.

Removing the air handler panel without the copper pipes is often necessary to see the heat strip tag. (There is usually four 5/16 inch hex screw holding the panel on the air handler).
 
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Old 01-24-13, 05:28 PM
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I was finally able to get up in the attic and pull the panel. I have not installed the thermostat yet. I've got some pictures below. The label indicates a Goodman hkr-15c linked here with specs. Looks like three strips? 14.3KW. Is this in total or each?

I did exchange the RTH6580WF to the RTH8580WF.

So, is it recommended I combine the "E" and "W2" wire together or leave the "E" wire taped off?

Thanks!

[ATTACH=CONFIG]8321[/ATTACH]

[ATTACH=CONFIG]8322[/ATTACH]

[ATTACH=CONFIG]8323[/ATTACH]

[ATTACH=CONFIG]8324[/ATTACH]
 
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Last edited by ron.p; 01-24-13 at 07:04 PM.
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Old 01-24-13, 08:52 PM
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I'd verify that Aux is feeding the white wire at the heat strips, connect W2 and tape off E.
 
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Old 01-25-13, 08:47 PM
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Please see the circles, closest thing I could find as I don't see the labels. White wire plugged in, is this the actual heat strip? I thought they were the three above.

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Old 01-26-13, 10:44 AM
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the heat strips are behind the sheet metal in the vicinity of the 3 limits above.
 
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Old 01-26-13, 02:02 PM
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OK, that's what I thought when I looked at the specs (w/ pic) earlier.

I'm still confused, I guess I'll do as earlier suggested and white wire from old "W2" to "E/AUX" on new and tape off the black old "E" wire.

If I am running just off heat strips and not the heat pump, easy way to tell other than getting a huge power bill? Does the outside unit still churn?
 
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Old 01-26-13, 02:08 PM
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If in emergency heat mode, the HP does NOT run. An amp meter will tell if 1 or 2 or all 3 strips are running if placed on different wires.
 
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Old 01-26-13, 03:01 PM
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Thanks for the quick reply. Hooked up, outside unit is running, air is moving.

By taping off the black "E" wire and not combining it with the white "W2" (manual says to shove them both in "E/AUX" port, I'll still get heat strip support, correct? I have no amp meter nor would I have the basic skill to use one.

Hate to watch the unit run and run and run with it 20 degrees outside and maintaining 72 inside.
 

Last edited by ron.p; 01-26-13 at 03:44 PM.
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Old 01-26-13, 06:32 PM
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TYPICAL HEAT PUMP OPERATION: HP runs almost non stop, aux heat kicks in as needed below 30F outdoor temp.
 
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Old 01-26-13, 06:48 PM
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Ok. Seems to be running ok, keeping 72 at the moment, about 20 outside, so strips must be kicking in.

I guess taping off the black wire eliminated the emergency heat function, not that we ever used it.

Thanks!
 
 

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