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airheatman, HVAC Technician
Category: HVAC
Satisfied Customers: 8327
Experience:  Furnace, A/C and heat pump specialist.
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I have a rheem prestige super quiet 2 stage 80 and a heat

Customer Question

hi...i have a rheem prestige super quiet 2 stage 80 and a heat pump. had it about 7 years a never worked the way i wanted it. the furnace never seems to run on first stage. i have been digging and digging. it is the rpgr model. so what i think i know is. gas is now cheaper where i live and i don't like the heat pump heat. i have raised the lock out temp on the tsat as high as i can so now furnace runs most of the time, which is what i want, but it still runs at full speed, even though the tstat honeywell is set for 2heat/1 cool. (i have tried every setting on the tstat and no low speed ever kicks in.) one of the installation manuals says set jumper 7 for this feature, my board does not have a jumper 7. it only has 4 dips on main board and 12 on board that controls the fan. then i read that this furnace with a heat pump requires a fossil fuel kit which i have verified is installed, and in the instructions for that kit it says once heat pump is locked out furnace will only run as if it only has one stage. if i am reading that right, that sucks because i want it to run quietly at a low speed in the background so i don't hear the damn thing. so then i thought i could just over ride the fan settings but that would not reduce the burner and it might get too hot. then i thought well maybe i can just wire it like a straight a/c and not use the heat pump function and then it would work? (btw i can't find a drawing anywhere that matches my control board) help
Submitted: 1 year ago.
Category: HVAC
Expert:  airheatman replied 1 year ago.

Tell me what thermostat you are using and if you have it set to conventional or heat pump.

Customer: replied 1 year ago.
vision pro 8000t...i have tried every setting. so right now, i disconnected the heat pump and wired it just 1 to 1, i.e. w to w, r to r, and furnace is working the way i want...but come summer? if you want me to rewire it back to try something i can do that too! thx
Expert:  airheatman replied 1 year ago.

Here is what I would do if you do not want the heat pump to work in heat mode.

At thermostat

Connect R to R and RC

Connect G to G

Connect Y to Y

Connect C wire to C

Connect the O/B wire to W

Connect the AUX wire to W2

The go to setup menu and select 9 (2 heat/1 cool multistage conventional) for function 0170 system type.

Expert:  airheatman replied 1 year ago.

At furnace connect the wire from W at thermostat to W and wire from W2 at thermostat to W2.

Expert:  airheatman replied 1 year ago.

Let me know if this works for you.

Customer: replied 1 year ago.
great, i will try that tomorrow...thank you have a great night!
Expert:  airheatman replied 1 year ago.

Sounds good.Let me know.

If you have further questions, please let me know.

Thanks for letting me work with you.If my answer has been polite, professional,and thorough, please click one of the ratings before you go. If you still need help let me know!.Expert is not paid for assisting you until you rate answer.Feel free to follow up for 30 days at no additional cost. Bonus always appreciated if you feel justified.

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Customer: replied 1 year ago. i wired per instructions...couple questions. 1. when i turn the fan on via the tsat it does not come on. 2. right now there are no wires from the heat pump connected to the furnace and thus not connected to the tsat. 3. blower still seems to be running on high. i read the installation instructions and they say i have to make sure jumper p7 is set correctly. here is link control board does not have a p7.
Expert:  airheatman replied 1 year ago.

1. Set function 0180 to 0 and see if it makes a difference on fan.

2. The only wires that should be connected to heat pump right now are C(Common) R (Power) and Y (Contactor control)

3.The link you sent is for a later year of the same model furnace.In those furnaces, they combined the fan and main board together.I am attaching a link for the manual for your furnace.

The board should recognize you have a 2 stage thermostat and operate accordingly.If not, you may have to add an isolation relay.See page 21 for instructions and details.

Customer: replied 1 year ago. i verified setting 180 is set to go.thanks for sending me the right manual.on the isolation relay, is that something i can go buy at Home Depot? I understand the wiring diagram just not sure where i get one
Expert:  airheatman replied 1 year ago.

Probably an appliance parts or hvac supply house.

Customer: replied 1 year ago.
thx...what about the fan?
Expert:  airheatman replied 1 year ago.

That may solve that issue also if the 8000 is not communicating with the control board.I would think as long as you have an R and G at thermostat connected to R and G at furnace it should work, but those variable speed communications are a bit iffy. I know the Nest , which is one of the best on market, will not even work with a variable speed fan.

Customer: replied 1 year ago.
ok, thx i will try that
Expert:  airheatman replied 1 year ago.

Let me know if this helps.

Customer: replied 1 year ago.
could you find what type of relay i need on the web and send me the link?
Customer: replied 1 year ago.
thx hope this fixes it
Expert:  airheatman replied 1 year ago.

Me too.Let me know

Customer: replied 1 year ago.
good afternoon super the isolation relay came in, the one you sent me the link on. i connected if per instructions of furnace. nothing was working, so i changed the tstat setting under 170 to 9. furnance started good thing, what i am trying to figure out now is how do i know the furnace is running on stage 1? blower sounds as loud as usual...AND when i try to turn on fan using tsat i get nothing. thx in advance
Expert:  airheatman replied 1 year ago.

You should see a difference between first and second stage.See pages 23 and 24 for explanation of how it should be doing

Customer: replied 1 year ago.
i have read that, so do i just sit at the furnace an hope it cycles through from 1st to 2nd? Also, what about the fan? And which is controlling which stage? seems like it's the tstat? which i am wondering if that is the problem with the fan etc...i replaced batteries but same results