Help Wiring a New Honeywell 8000 for dehum

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Old 06-20-19, 10:14 AM
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Help Wiring a New Honeywell 8000 for dehum

Hey! I just got my new thermostat. I've done this on other systems, but I need some guidance so I don't screw this up:

What I have:
Compressor: RPQL-048JEZ
Air Handler: RH2V4821MTANJA
http://pts.myrheem.com/docstore/webd...H1V_(-)H2V.pdf
Thermostat: Honeywell T6 Pro

What I am installing:
Thermostat: Honeywell T8321WF1001
Install Manual: https://forwardthinking.honeywellhom...ion_Manual.pdf


Current Wiring on existing thermostat:
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What I need to do:

1.) I need to change jumpers 9/10 in the Air Handler to be set to 'active' for dehumidification. See Page 32, section 3-13-7.

2.) Wire up existing thermostat Y, G, C, O/B, W2, and R to their respective terminals on the new 8000 Thermostat.

What I do not know:

1.) 8000 Pro Manual, Page 4, Bottom left indicates that I need to add a jumper between R and U1. So install that?

2.) Page 4 of the manual also says to remove the jumper from Rc and R for a two transformer system. I don't know what I have.

3.) Do I need to change any wiring in the air handler accordind to page 26, Section 3.12.9? I don't have a picture of that, perhaps that would be useful to see how it is currently done.

It would appear as though I need ONE MORE WIRE from the second U1 terminal on the t-stat to he ODD terminal on the air handler, i.e. Figure 22, Page 27 of air handler manual.


I want my thermostat to turn the fan on low speed for dehumidification. I don't have extreme humidity problems, but my home IS leaky because it's old and keeping it dry is nice during times when its just not quite hot enough to make the system run a lot.
 

Last edited by PJmax; 06-20-19 at 10:30 AM. Reason: added pic from link
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Old 06-20-19, 10:58 AM
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Welcome to the forums.

Y - yellow ---------------> Y
G - green ---------------> G
C - orange/brown ----> C
O/B - blue --------------> O/B
AUX - white -----------> AUX/E
R - red ------------------> R with jumper to Rc

You have a single transformer system.
U1 is nothing more than a thermostat controlled switch. So if you add a jumper from U1 to R then the U1 will switch 24v to the second U1 terminal. This second U1 terminal will connect to the ODD terminal. The U1 relay is programmed as dehumidification/normally open.

You have a single stage heat pump with back up electric heat.
That means you won't be using a two stage wiring diagram like Figure 22.
You'd be following figure 19.
 
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Old 06-20-19, 11:17 AM
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Awesome!

Figure 19 is the one I need to look at. I hope to have an additional unused wire in there somewhere to go from ODD to the Second U1 on my t-stat.

I understand that on mine, I am using the T-stat U1 and the Air Handler ODD.
But...for my own education....on the Figure 19 drawing, why do they show a Y2 connected to ODD?

Also, on my system, I can utilize a wire from L and L/A, yes?
 
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Old 06-20-19, 11:24 AM
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In that diagram.... they're using the thermostat switching to stage 2 cooling to change blower speed.
 
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Old 06-20-19, 06:58 PM
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The U1 relay is programmed as dehumidification/normally open.
I am confused. After reading your comment and the manual...it says:

If Active (On-Demand) Dehumidification is enabled and humidity in the conditioned space is below the humidity set-point on the humidistat or dehumidifying thermostat, a 24VAC input is applied to the ODD terminal on the control board. (See Figure 36)

Based on the Air Handler manual, page 34, If I have jumped R, Rc, and U1 and set my thermostat to 'NORMALLY OPEN', then this would send 0V to the second U1 and the ODD terminal, which would cause the air handler to run at 15% reduction.

Based on what this air handler wants at the ODD, shouldn't I be setting my thermostat to "NORMALLY CLOSED"?
 
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Old 06-22-19, 11:37 AM
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Edit to add Compressor Manual for my reference:
https://www.hvac.com/media/manuals/i...EMRPQL-JEZ.pdf
 
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Old 06-22-19, 03:36 PM
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IMPORTANT: An input from a humidistat or dehumidifying thermostat must be connected to the ODD thermostat pigtail (Green/Yellow) when DIP Switches 9 and 10 are
switched to the “ACTIVE” position. Otherwise, indoor air-flow will always be reduced by
15% in the cooling mode.

Yes, it looks like you have it figured out. Normally closed at the stat.
 
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Old 06-22-19, 03:42 PM
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Thanks Houston. Name:  thumb.jpg
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When I was reading the manual..... I was looking at humidification not dehumidification.
 
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Old 06-23-19, 08:47 AM
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Awesome. You guys are the best! Thanks a ton for the advice and insight. It’s much appreciated.
 
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Old 06-28-19, 02:45 PM
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Add two wires?

is there any issue with simply running a second 18/2 wire down along side the 18/6 so that I have enough wires?
 
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Old 06-28-19, 06:31 PM
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There is nothing wrong with running 2 extra wires.
I would mark the extra wires to avoid confusion in the future.
I usually just put 2 lines on the second red and 2 lines on the second white wire with a sharpie.
 
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Old 06-29-19, 03:30 PM
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This won’t work

They ran this wire when the walls were apart and they drilled a hole through a fire block that is barely big enough to get a 81/6 wire through. So, I need a dehumidifying stat that has WiFi AND can operate on two wires or whatever is already in the wall. Seems like one of the honeywell do this and have all the stuff in the air handler.
 
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Old 07-03-19, 06:26 PM
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I need to change gears a little.

I am looking at the EIM setup now, with two wires from the t-stat. Easy.

Now, on the EIM, the wiring is also pretty straightforward. I do not understand the W2 terminal. I have a W2 wire. But on the EIM, I have a separate terminal for AUX1/Emergency Heat. The original thermostat uses the same terminal for both W2 and AUX-E.

EIM Manual: How does the EIM get wired up to gain the emergency functionality?

https://customer.honeywell.com/resou...0s/69-2739.pdf
 
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Old 07-04-19, 10:33 AM
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Nevermind. Apparantly my reply did not edit. We're good.
 
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