Ruud Blower cycles on and off, HELP - http://www.hvacmechanic.com/ Forums
Original message
| crxcte
 |  "Ruud Blower cycles on and off, HELP"
, posted Sun 1 Jun 09:21  
I have an electric Ruud air handler UBHC-21J14SFC and the blower cycles on and off intermittently. When it cycles off a burnt smell can be detected. I disconnected the green fan wire from the t-sat and the fan still comes on. If the fan controller is the problem, is it located on the fan motor? What does it look like?
Chris
|
|
Replies:
|
| crxcte
| "Re(1):Ruud Blower cycles on and off, HELP" , posted Sun 1 Jun 09:42
Any way to wire the fan to stay on? Appreciate any replies.
Chris
|
| | theduke03
| "Re(2):Ruud Blower cycles on and off, HELP" , posted Sun 1 Jun 09:49
No. You either have a bad capacitor, motor, or control but will need a meter to verify these. I suspect a capacitor.
"My dad was the most feared furnace fighter in Northern Indiana."
|
| | crxcte
| "Re(3):Ruud Blower cycles on and off, HELP" , posted Sun 1 Jun 09:55
I have a meter, can you give me instructions to isolate the problem?
Chris
|
| | theduke03
| "Re(4):Ruud Blower cycles on and off, HELP" , posted Sun 1 Jun 10:01:
Shut off breaker to unit. short the 2 terminals on cap with a screwdriver to de-energize it then disconnect the capacitor. Set meter to ohms on the highest scale. Put your leads on the 2 terminals.
If cap is good ohms will drop towards 0 then rise up towards infinate. Then switch leads and repeat and you should get same result.
If cap is bad it will show low ohms or open/infinate and reading will not change much.
Start with that and post results.
"My dad was the most feared furnace fighter in Northern Indiana."
[this message was edited by theduke03 on Sun 1 Jun 10:03] |
| | crxcte
| "Re(5):Ruud Blower cycles on and off, HELP" , posted Sun 1 Jun 10:23
The ohms started at 5 and moved up to infinity, switched the leads on the meter and read again, the reading started at 1600 ohms moved down to single digits then moved up to infinity.
Chris
|
| | theduke03
| "Re(6):Ruud Blower cycles on and off, HELP" , posted Sun 1 Jun 10:32:
Great. Most likely the cap is ok. Now turn unit on and turn fan on. Check that proper voltage is being supplied to motor. You may have to wait untill the problem happens. When it does, check that voltage again. If voltage is present when motor stops running then motor is bad. If voltage disappears causing the blower to stop then it's most likely the control or relay(whichever it uses to control blower).
Is your filter clean?
"My dad was the most feared furnace fighter in Northern Indiana."
[this message was edited by theduke03 on Sun 1 Jun 10:33] |
| | crxcte
| "Re(7):Ruud Blower cycles on and off, HELP" , posted Sun 1 Jun 12:05
After the fan motor shut off there was no voltage going to it.
Chris
|
| | theduke03
| "Re(8):Ruud Blower cycles on and off, HELP" , posted Sun 1 Jun 12:15
Great. Most likely the problem is the control. Is that a blower relay or a circuitboard, Sequencer? If unsure then describe it.
"My dad was the most feared furnace fighter in Northern Indiana."
|
| | crxcte
| "Re(9):Ruud Blower cycles on and off, HELP" , posted Sun 1 Jun 12:26
Blower relay. If there a way to wire around it to get the fan to run non stop. The part number 42-23114-05.
Chris
|
| | theduke03
| "Re(10):Ruud Blower cycles on and off, HELP" , posted Sun 1 Jun 12:47:
Does it look like this?
Just verify that this is definately the bad part by making sure this relay coil has 24v to it(the 2 unlabeled terminals) when dropping power to the motor.
Then you can bypass the relay by connecting the 2 line voltage wires together.(Terminals COM and NO). You will probably have to cut, strip, and wirenut these. Then put on new connectors when you get the new relay. Or...
You can remove and tape off one of the 24v wires and move the wire from NO to NC. This way noyhing has to be cut. I would try this first.
Be sure to shut off power when making repairs.
"My dad was the most feared furnace fighter in Northern Indiana."
[this message was edited by theduke03 on Sun 1 Jun 12:54] |
| | crxcte
| "Re(10):Ruud Blower cycles on and off, HELP" , posted Sun 1 Jun 12:37
the blower relay has 2 black wires that goes through 2 separate contacts, one normally open the other normally closed. There is a G/Bk wire and Br wire that runs through the relay.
Chris
|
| | Houston204
| "Re(2):Re(10):Ruud Blower cycles on and off, H" , posted Sun 1 Jun 12:41:
Com to NO.
Connect power wire to the normally open wire for continuous operation.
"Tip of the Day" Remember to remove power first.
[this message was edited by Houston204 on Sun 1 Jun 12:44] |
| | crxcte
| "Re(3):Re(10):Ruud Blower cycles on and off, H" , posted Sun 1 Jun 13:03
Thanks, that worked, fan is running and were getting some cool air. Just in time, heat index to reach near 100 in Oklahoma today.
Chris
|
| | theduke03
| "Re(4):Re(10):Ruud Blower cycles on and off, H" , posted Sun 1 Jun 13:08
Who is better than us?
"My dad was the most feared furnace fighter in Northern Indiana."
|
| | crxcte
| "Re(5):Re(10):Ruud Blower cycles on and off, H" , posted Sun 1 Jun 21:02
Your the best. Now that I have the fan blowing constantly I turned on the ac and it doesn't cool. I checked the compressor and it is running. Measured the voltage at the relay and confirmed 24 volts. Relay contacts are clean and works. The compressor is running and the lines sweat. Checked the coil and its not frozen. Checked the freon and its full. Would the blower relay have anything to do with it not cooling?
Chris
|
| | theduke03
| "Re(6):Re(10):Ruud Blower cycles on and off, H" , posted Mon 2 Jun 07:00:
No. Not if blower is running properly. Is your filter clean? If so I would suspect a dirty coil(indoor or outdoor coil)
"My dad was the most feared furnace fighter in Northern Indiana."
[this message was edited by theduke03 on Mon 2 Jun 07:01] |
| | crxcte
| "Re(7):Re(10):Ruud Blower cycles on and off, H" , posted Mon 2 Jun 08:26
Changed all the in door return filters. Washed the coil outside. Did not clean the coil inside.
Chris
|
| | crxcte
| "Re(8):Re(10):Ruud Blower cycles on and off, H" , posted Tue 17 Jun 11:37
I need to verify the wiring on the air handler for the heater side. There is a white/blue and white/black for heating. How is it to be wired to the t-stat on a Ruud electric air handler?
Chris
|
|
|
|  |
|
