Heat, A/C, and fan stopped working


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Old 09-03-17, 09:47 AM
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Heat, A/C, and fan stopped working

The unit is a Rheem (heat pump, if that matters)

I tried jumping the R + G at the thermostat and it still doesn't turn on. Also checked the float switch at it appears dry as well. And obviously checked the breaker.

Then I got someone online to help me but then he got lost. He had me check the voltage on the following wires in the air handler. This was the result:

28vac between R and C
0vac between C and Y

Anyone got any ideas?
 
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Old 09-03-17, 10:36 AM
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Thread moved to heat pump forum.

28vac between R and C means the transformer is good and the system has power. 0v between C and Y means the stat is not calling for cool.

Remove thermostat from the base. Should pull off.
Check from ............
R to Y
R to G
R to O

24vac on all three would indicate a defective thermostat.
 
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Old 09-03-17, 01:45 PM
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And if I get 0vac on Y and G (no O wire)?

Based on this, is there anyway for me to 'hotwire' this thing, as it's really hot. lol

edit: So I had another thermostat here. I hooked it up and it won't even power up (the original thermostat used batteries).
 

Last edited by mattressfish; 09-03-17 at 02:05 PM.
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Old 09-03-17, 02:12 PM
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Sorry..... your Rheem uses a B terminal only for heat.

At the air handler..... try jumping R to Y and G.
If this works.... something is opening the R wire.
Double check the float is operating correctly.
 
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Old 09-03-17, 02:19 PM
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Any chance you can explain that a little more in depth, as I really don't see those designations in the air handler. If it helps, this is what I'm working with










edit: Also, is the float open or closed by default? Can I just short those wires to test?
 
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Old 09-03-17, 02:33 PM
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Okay, just checked the float and appears to be in working order. Circuit is closed when it's down, and open when I raise it.
 
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Old 09-03-17, 02:38 PM
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You found R and C. The Y = yellow and the G= green
 
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Old 09-03-17, 02:45 PM
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Sorry about my apprehensiveness. I'm now dealing with stuff that I don't fully understand and want to make sure that I don't screw something up. The R and C I tested were on the circuit board. There is a yellow and green wire in there, but I don't think those are the ones you're talking about..

 
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Old 09-03-17, 04:19 PM
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This is the point where the air handler joins the thermostat and to the outside condensor.
We are interested in the thermostat cable. Carefully pull the splices out and apart to see them better. Don't take any connections apart until you can see where they go.

Remove the wire nut from the red wire connection and touch it to the green wire connection. That should start the blower. Connecting the red wire to the yellow will start the outside condensor running although it may take 5 minutes.

There is a.....
red wire for 24vac to the stat
blue wire for common C to the stat
green wire for blower control
orange wire for ??
white wire for electric reheat
brown wire for B - 24vac power to condensor for heating mode.
 
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Old 09-03-17, 04:36 PM
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Okay, so I touched the red wire(s) to the green wire(s) and the blower did not kick on.
 
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Old 09-03-17, 04:39 PM
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Ok..... since you have a meter.... check that red wire to either any metal chassis or to the C terminal inside that control box.
 
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Old 09-03-17, 04:49 PM
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I'm reading 0vac on that red wire
 
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Old 09-03-17, 04:51 PM
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Ok... now you need to follow the heavy red wire towards the control box. You told us you had power from R to C which means that red wire should be powered. We need to find out what is in that red line that is stopping the 24vac. The float switch should be one item in that red line.
 
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Old 09-03-17, 05:06 PM
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Okay, so the float switch runs 'through' a yellow wire. One side connects to the thermostat pairs, the other side connects to the wire that goes to the condenser.

The red wire terminates on the PCB in a different place than I checked originally. Hopefully this pic makes sense:

 
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Old 09-03-17, 05:31 PM
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...and I feel like a complete idiot. Hidden under some of the wires on the PCB is the fuse. It's blown.
 
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Old 09-03-17, 05:39 PM
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Ahhhh..... the hidden fuse.
 
 

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