air handler blues
#1
09-12-07, 04:46 PM
air handler blues
I have noticed that intermittantly, the air handler skips an "on" cycle, when the outside unit kicks on. My fix for this has been to set the tstat control from "cool" to "off" and then to "heat" then back to "off".I turned the fan switch from "auto" to "on", to see if the fan would come on and it does. wait a few minutes and turn it back to "cool", after a short delay it comes on. Fan motor is good, thermostat control is good, capacitor is good. I don't have a system drawing to see what parts wire in the line
#2
09-12-07, 09:25 PM
Check blower relay or the blower control board. Sounds like you can have a time delay on that blower control board . The G wire should go to it in the blower unit.
Can jump R to G at tstat should get fan if you dont after a short time can be fan control in the tstat .
Can jump R to G at tstat should get fan if you dont after a short time can be fan control in the tstat .
#3
09-14-07, 05:03 PM
I installed a new thermostat control when it started this but didn't fix it. Where would the blower relay or the blower control board. be at ? 
The fan work fine if you go"cool" to "off" and then to "heat" then back to "off " then "cool"
.
The fan work fine if you go"cool" to "off" and then to "heat" then back to "off " then "cool"
.
#5
09-16-07, 02:50 PM
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I would have to agree. If jumpering r to g doesn't turn on the blower, you would have a bad board or relay. Sometimes these can fail intermittently.
#12
09-21-07, 05:20 AM
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That pretty much nails it down. Your relay is bad. On newer units the relay is on a circuit board. In this case, you replace the board. Its easy to find, the motor wires connect to it.
It's not unusual to have a relay fail intermittently. This can be a little frustrating. It may work perfectly 100 times in a row, then when no one is watching, it doesn't work.
It's not unusual to have a relay fail intermittently. This can be a little frustrating. It may work perfectly 100 times in a row, then when no one is watching, it doesn't work.
#13
09-21-07, 03:06 PM
COULD MY DEFROST COTROL CIRCUIT BOARD IN MY OUTDOOR UNIT HAVE SOMETHING TO DO WITH THIS I THINK THAT IT MAY NOT BE DEFROSTING RIGHT? IF NOT I LOOK IN THE AIR HANDLER NO CIRCUIT BOARD RELAY IN THERE. I SEE WHAT LOOKS LIKE TO FAN COIL SEQUENCER BLOWER CONTROL TIME DELAY RELAY ONE HAS WIRE LEADS FROM FAN GOING TO IT. THE OTHER LOOKS LIKE IT GOES TO HEAT STRIPS. WHAT DO YOU THINK
#15
09-23-07, 11:54 AM
Originally Posted by R*JRT
COULD MY DEFROST COTROL CIRCUIT BOARD IN MY OUTDOOR UNIT HAVE SOMETHING TO DO WITH THIS I THINK THAT IT MAY NOT BE DEFROSTING RIGHT? IF NOT I LOOK IN THE AIR HANDLER NO CIRCUIT BOARD RELAY IN THERE. I SEE WHAT LOOKS LIKE TO FAN COIL SEQUENCER BLOWER CONTROL TIME DELAY RELAY ONE HAS WIRE LEADS FROM FAN GOING TO IT. THE OTHER LOOKS LIKE IT GOES TO HEAT STRIPS. WHAT DO YOU THINKthere still has to be a relay to run the indoor fan on a call for cooling, it's probably wired in parallel to the sequuncer trace the wires back from the fan motor to find it the problem as you describe it would involve the defrost board.
#17
09-24-07, 03:04 PM
COULD MY DEFROST COTROL CIRCUIT BOARD IN MY OUTDOOR UNIT HAVE SOMETHING TO DO WITH THIS I THINK THAT IT MAY NOT BE DEFROSTING RIGHT? IF NOT I LOOK IN THE AIR HANDLER NO CIRCUIT BOARD RELAY IN THERE. I SEE WHAT LOOKS LIKE TO FAN COIL SEQUENCER BLOWER CONTROL TIME DELAY RELAY ONE HAS WIRE LEADS FROM FAN GOING TO IT. THE OTHER LOOKS LIKE IT GOES TO HEAT STRIPS. WHAT DO YOU THINK
the interior fan cut out on heat or cool
the interior fan cut out on heat or cool
#18
09-26-07, 11:16 AM
Originally Posted by R*JRT
COULD MY DEFROST COTROL CIRCUIT BOARD IN MY OUTDOOR UNIT HAVE SOMETHING TO DO WITH THIS I THINK THAT IT MAY NOT BE DEFROSTING RIGHT? IF NOT I LOOK IN THE AIR HANDLER NO CIRCUIT BOARD RELAY IN THERE. I SEE WHAT LOOKS LIKE TO FAN COIL SEQUENCER BLOWER CONTROL TIME DELAY RELAY ONE HAS WIRE LEADS FROM FAN GOING TO IT. THE OTHER LOOKS LIKE IT GOES TO HEAT STRIPS. WHAT DO YOU THINK
the interior fan cut out on heat or cool
the interior fan cut out on heat or cool
#19
10-10-07, 08:29 PM
OK I Have replaced both DELAY RELAY inside air handler and capacitor on motor also thermostat it work fine after replacement of parts for 5 days and its right back to the air handler skips an "on" cycle, when the outside unit kicks on the blower don't about every other day or so .
it work fine after replacement of parts for 5 days and its right back to the air handler skips an "on" cycle, when the outside unit kicks on the blower don't about every other day or so .
#20
10-11-07, 11:43 AM
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Hmmmmm. On some units, the defrost board may control the indoor blower at certain times. Such systems use a low pressure switch to initiate the defrost cycle rather than a timer.
This type of setup can be a little tricky to diagnose.
This type of setup can be a little tricky to diagnose.
#22
10-12-07, 06:54 AM
Originally Posted by R*JRT
l'm open to anything that my help me to get it working before it gets cold! The unit is 10 year old GMC
The unit is 10 year old GMCjust because the delay relay is new don't assume it's a good one.
#23
10-12-07, 07:30 AM
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I'd have to agree. It looks like we are back to the blower time delay relay or its associated wiring.
Was any work done to the unit at a previous time? Perhaps it was miswired.
Was any work done to the unit at a previous time? Perhaps it was miswired.
#26
10-14-07, 06:02 AM
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I've done that a few times too. Those Goodman time delay relays can have a short life and often fail intermittently. I have seen them go bad in less than 2 years.
Perhaps the wrong relay was replaced. The blower td relay looks like an electric heat stack relay with 5 connections. 2 for the 24 coil and 3 others labeled 1,2 and 3.
Post some pics if possible.
Perhaps the wrong relay was replaced. The blower td relay looks like an electric heat stack relay with 5 connections. 2 for the 24 coil and 3 others labeled 1,2 and 3.
Post some pics if possible.
