Nordyne / Partners Choice Package Units: R4GA

Re: Flashing Code 1 - Open Limit Circuit

The R4GA package unit has two limits wired in series:

• Primary Heat Exchanger Limit (auto reset) - 165 deg
• Burner Roll-Out Limit (manual reset)

Possible Causes (From Most to Least Likely):

1. Primary Limit Open
   • Low Airflow
     • Dirty Filter
     • Clogged Evaporator
     • No Blower Operation
     • Restricted Ductwork
   • Over-Fired
   • Bad Limit
2. Roll-Out Switch Open
   • Bad Heat Exchanger
   • Bad Limit
3. Bad Control Board

CHECKOUT

1. Test Limit Circuit
   • With a call for heat (24VAC on "W"), check for power through the limit circuit.
     • Check for 24VAC power at the control board molex plug on terminal 3 and terminal 8.
       • Check between "C" and terminal 3, then between "C" and terminal 8.
2. Check Limits
   • Without pulling wires off limits (to avoid accidental reset), check for 24VAC power between "C" and each side of each limit.
     • Power on one side of the limit and not the other = Open Limit