Graco Reactor E-XP1 Troubleshooting Manual page 6

Reactor Error Code Trouble Shooting Guide
2) One of the over temperature switches (Ref # 308) picked up a high fluid temp
greater than 230° F (110°C). At 190° F (88°C) the contacts close again.
 Check continuity of the over temperature switches by removing the J1/SENSOR B
connector from the temperature control module socket. On the plug end check the
resistance across pins 1 & 2 and pins 3 & 4 for continuity, (nearly zero ohms).
See figure above
3) Either the "A" or the "B" Thermocouple has failed, or is not in contact with a
working heater element.
 Check and see if the "A" or the "B" Thermocouple is damaged or not making contact
with a working heater element. See section Thermocouple in manual 312066 E-
Series, 312063 H-Series, 313540 H-VR-Series.
Rev 2.6 (02/2014) Page 6