diff --git a/checker/check.go b/checker/check.go
index 03aa5283e..e874e2391 100644
--- a/checker/check.go
+++ b/checker/check.go
@@ -170,27 +170,6 @@ func (triggerChecker *TriggerChecker) handleFetchError(checkData moira.CheckData
 	)
 }
 
-func (triggerChecker *TriggerChecker) reactOnSourceUnavailableError(checkData moira.CheckData, err error) moira.CheckData {
-	timeSinceLastSuccessfulCheck := checkData.Timestamp - checkData.LastSuccessfulCheckTimestamp
-	if timeSinceLastSuccessfulCheck >= triggerChecker.ttl {
-		checkData.State = moira.StateEXCEPTION
-		checkData.Message = fmt.Sprintf("Remote server unavailable. Trigger is not checked for %d seconds", timeSinceLastSuccessfulCheck)
-
-		var comparingErr error
-		checkData, comparingErr = triggerChecker.compareTriggerStates(checkData)
-		if comparingErr != nil {
-			triggerChecker.logger.Error().
-				Error(comparingErr).
-				String(moira.LogFieldNameTriggerID, triggerChecker.triggerID).
-				Msg("cannot compare trigger states")
-		}
-	}
-
-	logTriggerCheckException(triggerChecker.logger, triggerChecker.triggerID, err)
-
-	return checkData
-}
-
 // handleUndefinedError is a function that check error with undefined type.
 func (triggerChecker *TriggerChecker) handleUndefinedError(checkData moira.CheckData, err error) error {
 	triggerChecker.metrics.CheckError.Mark(1)
diff --git a/checker/check_test.go b/checker/check_test.go
index 994d983ea..cc6a880ba 100644
--- a/checker/check_test.go
+++ b/checker/check_test.go
@@ -2066,7 +2066,7 @@ func TestTriggerChecker_handleFetchError(t *testing.T) {
 						Metric:         triggerChecker.trigger.Name,
 					},
 					true,
-				).Return(nil).Times(2)
+				).Return(nil).Times(2) // this is strange... why 2?
 				dataBase.EXPECT().SetTriggerLastCheck(
 					triggerChecker.triggerID,
 					&expectedCheckData,
@@ -2076,6 +2076,120 @@ func TestTriggerChecker_handleFetchError(t *testing.T) {
 				err := triggerChecker.handleFetchError(newCheckData(triggerChecker.lastCheck, triggerChecker.until), givenErr)
 				So(err, ShouldBeNil)
 			})
+
+			Convey("time since last successful check < triggerChecker.ttl", func() {
+				triggerChecker.ttl = 30
+				triggerChecker.lastCheck.LastSuccessfulCheckTimestamp = triggerChecker.until - 15
+
+				expectedCheckData := moira.CheckData{
+					Score:                        0,
+					Metrics:                      triggerChecker.lastCheck.Metrics,
+					State:                        triggerChecker.lastCheck.State,
+					Timestamp:                    triggerChecker.until,
+					EventTimestamp:               triggerChecker.until,
+					LastSuccessfulCheckTimestamp: triggerChecker.lastCheck.LastSuccessfulCheckTimestamp,
+					Message:                      "",
+					MetricsToTargetRelation:      map[string]string{},
+				}
+
+				dataBase.EXPECT().SetTriggerLastCheck(
+					triggerChecker.triggerID,
+					&expectedCheckData,
+					triggerChecker.trigger.ClusterKey(),
+				).Return(nil).Times(1)
+
+				err := triggerChecker.handleFetchError(newCheckData(triggerChecker.lastCheck, triggerChecker.until), givenErr)
+				So(err, ShouldBeNil)
+			})
+		})
+
+		Convey("with bad functions, problems in expressions, etc", func() {
+			errorsList := []error{
+				local.ErrorUnknownFunction(errors.New("unknown func \"dance\"")),
+				local.ErrorEvalExpression(errors.New("eval expr"), "badExpr(dancing.mops"),
+				remote.ErrRemoteTriggerResponse{
+					InternalError: errors.New("user write bad target"),
+					Target:        "bad target",
+				},
+			}
+
+			for i, givenErr := range errorsList {
+				Convey(fmt.Sprintf("Case %v: %T", i+1, givenErr), func() {
+					expectedCheckData := moira.CheckData{
+						Score:                        int64(100_000),
+						Metrics:                      triggerChecker.lastCheck.Metrics,
+						State:                        moira.StateEXCEPTION,
+						Timestamp:                    triggerChecker.until,
+						EventTimestamp:               triggerChecker.until,
+						LastSuccessfulCheckTimestamp: triggerChecker.lastCheck.LastSuccessfulCheckTimestamp,
+						Message:                      givenErr.Error(),
+						MetricsToTargetRelation:      map[string]string{},
+					}
+
+					dataBase.EXPECT().PushNotificationEvent(
+						&moira.NotificationEvent{
+							IsTriggerEvent: true,
+							TriggerID:      triggerChecker.triggerID,
+							State:          moira.StateEXCEPTION,
+							OldState:       triggerChecker.lastCheck.State,
+							Timestamp:      triggerChecker.until,
+							Metric:         triggerChecker.trigger.Name,
+						},
+						true,
+					).Return(nil).Times(1)
+					dataBase.EXPECT().SetTriggerLastCheck(
+						triggerChecker.triggerID,
+						&expectedCheckData,
+						triggerChecker.trigger.ClusterKey(),
+					).Return(nil).Times(1)
+
+					err := triggerChecker.handleFetchError(newCheckData(triggerChecker.lastCheck, triggerChecker.until), givenErr)
+					So(err, ShouldBeNil)
+				})
+			}
+		})
+
+		Convey("with undefined err", func() {
+			givenErr := errors.New("some undefined error")
+
+			checkMetrics, err := metrics.ConfigureCheckerMetrics(
+				metrics.NewDummyRegistry(),
+				[]moira.ClusterKey{moira.DefaultLocalCluster},
+			).GetCheckMetricsBySource(moira.DefaultLocalCluster)
+			So(err, ShouldBeNil)
+
+			triggerChecker.metrics = checkMetrics
+
+			expectedCheckData := moira.CheckData{
+				Score:                        int64(100_000),
+				Metrics:                      triggerChecker.lastCheck.Metrics,
+				State:                        moira.StateEXCEPTION,
+				Timestamp:                    triggerChecker.until,
+				EventTimestamp:               triggerChecker.until,
+				LastSuccessfulCheckTimestamp: triggerChecker.lastCheck.LastSuccessfulCheckTimestamp,
+				Message:                      givenErr.Error(),
+				MetricsToTargetRelation:      map[string]string{},
+			}
+
+			dataBase.EXPECT().PushNotificationEvent(
+				&moira.NotificationEvent{
+					IsTriggerEvent: true,
+					TriggerID:      triggerChecker.triggerID,
+					State:          moira.StateEXCEPTION,
+					OldState:       triggerChecker.lastCheck.State,
+					Timestamp:      triggerChecker.until,
+					Metric:         triggerChecker.trigger.Name,
+				},
+				true,
+			).Return(nil).Times(1)
+			dataBase.EXPECT().SetTriggerLastCheck(
+				triggerChecker.triggerID,
+				&expectedCheckData,
+				triggerChecker.trigger.ClusterKey(),
+			).Return(nil).Times(1)
+
+			err = triggerChecker.handleFetchError(newCheckData(triggerChecker.lastCheck, triggerChecker.until), givenErr)
+			So(err, ShouldBeNil)
 		})
 	})
 }
diff --git a/metric_source/local/errors.go b/metric_source/local/errors.go
index b9605024f..c4f43656a 100644
--- a/metric_source/local/errors.go
+++ b/metric_source/local/errors.go
@@ -58,6 +58,13 @@ type ErrEvalExpr struct {
 	target        string
 }
 
+func ErrorEvalExpression(err error, target string) ErrEvalExpr {
+	return ErrEvalExpr{
+		internalError: err,
+		target:        target,
+	}
+}
+
 // Error is implementation of golang error interface for ErrEvalExpr struct.
 func (err ErrEvalExpr) Error() string {
 	return fmt.Sprintf("failed to evaluate target '%s': %s", err.target, err.internalError.Error())
diff --git a/metric_source/local/eval.go b/metric_source/local/eval.go
index 4b429d189..5b4dacf47 100644
--- a/metric_source/local/eval.go
+++ b/metric_source/local/eval.go
@@ -95,10 +95,7 @@ func (eval *evaluator) Eval(
 		} else if isErrUnknownFunction(err) {
 			err = ErrorUnknownFunction(err)
 		} else {
-			err = ErrEvalExpr{
-				target:        exp.ToString(),
-				internalError: err,
-			}
+			err = ErrorEvalExpression(err, exp.ToString())
 		}
 	}