diff --git a/frappy_psi/ips_mercury.py b/frappy_psi/ips_mercury.py
index 467f9eb..045adfd 100644
--- a/frappy_psi/ips_mercury.py
+++ b/frappy_psi/ips_mercury.py
@@ -28,9 +28,9 @@ from frappy_psi.magfield import Magfield, SimpleMagfield, Status
 from frappy_psi.mercury import MercuryChannel, off_on, Mapped
 from frappy.states import Retry
 
-Action = Enum(hold=0, run_to_set=1, run_to_zero=2, clamped=3)
+Action = Enum(hold=0, run_to_set=1, run_to_zero=2, clamped=3, not_found=4)
 hold_rtoz_rtos_clmp = Mapped(HOLD=Action.hold, RTOS=Action.run_to_set,
-                             RTOZ=Action.run_to_zero, CLMP=Action.clamped)
+                             RTOZ=Action.run_to_zero, CLMP=Action.clamped, NOT_FOUND=Action.not_found)
 CURRENT_CHECK_SIZE = 2
 
 
@@ -161,6 +161,7 @@ class Field(SimpleField, Magfield):
         if self.switch_heater == self.switch_heater.on:
             self.__persistent_field = current
             self.forced_persistent_field = False
+            self._field_mismatch = False
             return current
         pf = self.query('DEV::PSU:SIG:PFLD')
         if self.__persistent_field is None: