Rheem - Model #: RRGG-05N31JKR - Furnace Problem
#41
10-05-14, 11:45 AM
Member
Thanks Houston204!
OP stated in post #37:
Based on those observations one would you conclude it is the relay, correct?
Should the OP ground the transformer common before replacing the FDR?
A short in the wiring to the body of the unit could complete a circuit since the 24 volt common wire is not grounded at the transformer.
We can prove it is the relay and not the wiring by unplugging these wires with the red check and blue check at the relay one at a time.
We can prove it is the relay and not the wiring by unplugging these wires with the red check and blue check at the relay one at a time.
I have removed the black wire with white strip going to W thermostat. The furnace will still run in COOL mode.
But if I remove the black wire from the FCC terminal 1 that goes to the fan and limit control (FCC) the A/C works properly and the furnace does not come on.
When I remove the gray wire on blower relay terminal 1, only the inducer motor starts.
But if I remove the black wire from the FCC terminal 1 that goes to the fan and limit control (FCC) the A/C works properly and the furnace does not come on.
When I remove the gray wire on blower relay terminal 1, only the inducer motor starts.
Should the OP ground the transformer common before replacing the FDR?
#42
10-05-14, 12:01 PM
Forum Topic Moderator
I have been wondering if grounding the common wire would help as well.
I would measure 24 volt common to ground at the transformer with a meter before grounding it and take an ohm reading across the FDR coil but I don't think the OP has a multimeter.
I wasn't sure if these wires were isolated at the FDR or at the other end of these wires.
I would measure 24 volt common to ground at the transformer with a meter before grounding it and take an ohm reading across the FDR coil but I don't think the OP has a multimeter.
I wasn't sure if these wires were isolated at the FDR or at the other end of these wires.
#43
10-05-14, 12:40 PM
I do have a voltmeter with beep function.
I removed the black wire with white stripe from the FDR terminal 1.
I removed the black wire going to FCC from the FDR at terminal 1.
Do you have any recommendations on a 24V SPST relay to replace the FDR?
I removed the black wire with white stripe from the FDR terminal 1.
I removed the black wire going to FCC from the FDR at terminal 1.
Do you have any recommendations on a 24V SPST relay to replace the FDR?
#44
10-05-14, 12:47 PM
Forum Topic Moderator
Amazon.com: Mars 90290 SPST 24V RELAY 1 Pack: Home Improvement
Relays are cheap. It still seems as if 2 problems may be present.
A volt meter would be much cheaper than calling a pro to help you if this problem persists with a new relay, and I suspect that it will. I want to know from where we are getting a completed 24 volt circuit, a shorted relay coil, backfeed or a shorted wire.
http://www.amazon.com/dp/B00E3XA0IM/...I1EAZJ5R8AQZSZ
Relays are cheap. It still seems as if 2 problems may be present.
A volt meter would be much cheaper than calling a pro to help you if this problem persists with a new relay, and I suspect that it will. I want to know from where we are getting a completed 24 volt circuit, a shorted relay coil, backfeed or a shorted wire.
http://www.amazon.com/dp/B00E3XA0IM/...I1EAZJ5R8AQZSZ
#45
10-05-14, 09:12 PM
Member
I was reviewing some of the photos the OP posted. In one of the photos it shows the black wire coming out of the roll-out switch wire-nutted with a black wire that apparently goes to the ignition module and a gray wire that appears to go directly to the gas valve. Checking the schematic it does not appear the gray wire should be going to the gas valve.
Last edited by firedawgsatx; 10-05-14 at 09:49 PM.
#46
10-06-14, 03:46 AM
Forum Topic Moderator
That is a good catch. It does appear to go from the rollout switch to the gas valve. We could use a closer look at this area. Black should connect from the rollout to an intermittent pilot module.
#48
10-10-14, 08:47 AM
Forum Topic Moderator
A volt meter to measure for 24 volts AC would make testing for the source of this problem much more reliable.
#49
10-10-14, 09:52 AM
Member
I do have a voltmeter with beep function.
Here are some tests you can do:
1. Measure for 24 volts from common to ground at the transformer. Use terminal #3 on the FDR as the common test point. Set meter to volts AC. Place red lead on FDR terminal 3 and the other lead to a bare spot on the cabinet or unpainted screw on the chassis.
2. Take an ohm reading across the FDR coil. Shut power off to unit. Set meter to ohms. Remove wires from terminals 1 and 3. Place one lead on terminal 1 and one lead on terminal 3.
3. Shut power off. Inside the unit, unwire the white wire and black/white stripe wire from the wire-nut and keep wires from touching any others or anything else. Turn power back on. Set thermostat to COOL several degrees below room temperature. Set meter to volts AC. Measure for 24 volts between the white (thermostat "W" wire) and common and then the black/white wire to common. Use terminal #3 on the FDR as the common test point.
Post the readings. Please post some photos of the wires connected to the gas valve and to the ignition module.
#50
10-26-14, 07:49 PM
Finally, I have found the problem.
It is the black wire with the red strip that was connected to the FDR #3 going to the thermostat black wire. That wire was not connected to the thermostat but was shorted with the R and G thermostat wires. The black wire with red strip on the FDR #3 is not on the schematic as well. After disconnecting the wire from FDR, A/C and furnace operate normally now.
Thank you guys for your help.
It is the black wire with the red strip that was connected to the FDR #3 going to the thermostat black wire. That wire was not connected to the thermostat but was shorted with the R and G thermostat wires. The black wire with red strip on the FDR #3 is not on the schematic as well. After disconnecting the wire from FDR, A/C and furnace operate normally now.
Thank you guys for your help.
