Monday, March 10, 2014

Rheem Heat Pump Thermostat Replacement



I have 2 Rheem heat pumps in my home that had regular mercury type thermostats. I decided to install a Honeywell RTH6350 programmable tstat on both units. I followed the directions and wiring digrams for both. One unit worked perfectly after the installtion but the other had issues. When heat was called for, it seemed like very little heat was coming out of the register and little or no air flow. I took the cover off the blower unit and put the fan on ON and the fan was working. I put the original tstat back on and things worked perfectly again. The model number of the one having the issues is Rheem RHQA-0810B. The wiring I had for the Honeywell hookup was as follows:
red - R with jumper to RC
Yellow -Y
Orange - O/B
Green - G
White - Aux with jumper to E
Blue - Not connected per instructions
Black (X) - Not connected per instructions.
As far as the post-installation setup, I believe my options-selected were as follows:
1-5
2-0 (since O was connected to O/B as instructed)
6-5
8-9
13-1
14-0
I tried calling the Honeywell help line and they were no help. Any ideas on what I can try to resolve this? Thanks.

What was blue tied to?
Is the outdoor unit Rheem/Ruud as well?
If so, set up#2 needs to be 1.
6 and 8, I'd suggest 3 for better comfort.

The outdoor unit is Rheem. The blue was to blue on the original tstat and it says not to use that wire on the RTH6350 setup. On function 2 the manual stated that if you connected an O to the O/B terminal to use option 0 for that function. On 6 8, it says that that a 3 is for hot water or HE gas furnace. Will those work with the heat pump correctly?

what color wires were on what terminals on the old stat. Lets start there.

Red - R
Yellow -Y
Orange - O
Blue - B
Green - G
White - W2
black - X
Jumper from W2 to E
Thanks.

You don't use the orange on rheem, not sure why they used the o since they use B. You want the blue on the o/b.

Are you saying that if from the wire setup in the first post I leave everything the same but replace the orange wire on the O/B terminal on the RTH6350 and change the function 2 setting to 1 it should work correctly?
And I should change the functions 6 8 to 3 as well as mentioned earlier?
Thanks again.

Yes, move the blue wire in place of the orange, and make those changes.

Thanks for the info. I'll make those changes and let you know how it works out.

it is possible that this stat will not work because you have o and b hooked up on your old stat and may need a stat with separate o and b terminals.

Give is the make and model of your inside unit and outside. Also, is this zoned?

The inside unit is an RHQA-0810B. I'll get the outside model number next time I'm home and post it. Thanks.

Okay -
The inside model is RHQA-0810B and the outside unit is RPMA-024JAZ. Let me know if you need any further information - thanks.

I'm not seeing anything special with this.. So, not sure why O/Orange was used. Did you look at the air handler and trace the orange wire to see where it went to?

At the air handler the orange is connected to a purple wire.

Not sure why they tie it to this purple wire, in the diagram it shows goes to an optional Defrost Heat Sensor.
It looks like it should be tied to the HP's defrost wire. So, when the unit goes into defrost, the purple wire powers up the heat strips.

But that wouldn't explain the issues I had with the new tstat not working correctly, would it?

Your old stat had B hooked up so you had the HP working, and Made me wonder about your cooling bill! Cuz O is powered up in cooling mode.

So what would be the your suggested configuration for the wires? Leaving the blue not connected like before and leaving everything else as posted previously for the new TSTAT? If so, since it didn't seem to work that way previously, do you think there might me an issue the the new tstat?
Like a said earlier, I hooked up 2 of the new honeywell tstats on the same day and the other is working fine. The only difference in in the wiring is that the one that is working didn't have an orange wire connected.

what did you do with the blue wire on the other stat? My suggestion is to hook everything up but orange and configure the system to use b with heating

Put the Blue wire on the O/B on the stat, and tuck the orange wire into the wall. Go to the air handler, and see were the defrost wire is going to.

OK - I tracked all of the connections and here they are:
Old TSAT:
red-red
yellow - yellow
orange - orange
blue - blue
green - green
white - W2
black - X
Jumper W2 to E
There are 3 sets of wires going to the air handler:
#1 (4 wires)
blue - blue #2
yellow - red #3
brown - black #2, air handler brown
orange - air handler purple
#2 (6 wires)
green - air handler black
black - brown #1, air handler brown
red - air handler red
white - air handler black
blue - blue #1
yellow - white #3
#3 (2 wires)
red - yellow #2
white - yellow #1
Air handler (5 wires, connections listed above)
black #2
black #2
red
purple
brown
Any suggestions or ideas? Thanks.

Old STAT:
red-red 24 volt power
yellow - yellow compressor
orange - orange not used
blue - blue reversing valve
green - green fan
white - W2 heat strip
black - X common
Jumper W2 to E
There are 3 sets of wires going to the air handler:
#1 (4 wires)outdoor unit
blue - blue #2
yellow - red #3
brown - black #2, air handler brown
orange - air handler purple
It is odd that we do not suppy 24 volts to the outdoor unit, but the diagram I see agrees with this.
#2 (6 wires)Stat
green - air handler black
black - brown #1, air handler brown
red - air handler red
white - air handler black
blue - blue #1
yellow - white
Notice that stat orange is not used
#3 (2 wires)Float switch
red - yellow #2
white - yellow #1
Air handler (5 wires, connections listed above)
black #2
black #2
red
purple
brown
The 2 blacks had a small colored stripe at one time.

Sorry, I missed one connection on the list that I mentioned earlier in the thread, at the air handler the orange is connected to a purple wire.

I see that the outdoor unit orange connects to air handler purple.
How many orange wires are connected to air handler purple?

Sorry, only one. The outdoor unit orange to air handler purple. So as mentioned earlier, the orange should not be connected to the new TSTAT? Also, since I put the old tstat back up until I get the new one working, should the orange wire not be used with the old tstat either?

Connecting orange to your stat will risk popping a low voltage fuse or damaging your transformer (if a low voltage fuse or low voltage breaker is not present) if it touches the air handler body .
I would not connect orange to the stat. This wire would be energized when a cooling demand is present.

Take the cover off the unit outside, and see where that orange is tied at.

Orange is going to be defrost (D or W).

I'll check/verify the connection on the outdoor unit. It will probably be on the weekend since it gets dark so early. I'll post what I find then - Thanks.






Tags: rheem, heat, pump, thermostat, blue blue, outdoor unit, handler purple, orange wire, black black, blue blue yellow, blue yellow, brown handler