Graco Reactor E-XP1 Troubleshooting Manual page 9

Reactor Error Code Trouble Shooting Guide
4) Heater modules failed to turn off any heat zone, causing a run-away condition.
 Exchange zone module with another one. Turn zone on and check for error. If error
moves to another zone, replace the faulty module. (When there is a high current error, the
LED on that zone's module will turn red while the error is displayed.
 Check and see if the heater module (BLUE) is turning off when the unit hits the set point
temperature.
o For "A" heater test points T4 on 238CR & T2 on POD A connector.
o For "B" heater test points T6 on 238CR & T2 on POD B connector.
o For HOSE test points T1 on 183 CB HOSE & T1 on POD HOSE connector.
5) If fluid is below 190° F (88°C) and you are still getting the high temp error:
Causes:

Faulty connection of either of the "A" & "B" thermocouple to the heater control
module
Rev 2.6 (02/2014)
o Set the "A", "B", and HOSE set point 10°F/C below the actual
temperature, and turn the heat zones on one at a time. The red light on
the display above the zone should be blinking and there should be little
to no voltage on the voltmeter.
 Measuring voltage while the red light is blinking would
indicate that the output on the heater module has failed.
Replace the heater module. Note: all 3 modules are the same
and can be swapped for troubleshooting.
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