diff --git a/app/control.js b/app/control.js
index f7668ac..d0ddcc1 100644
--- a/app/control.js
+++ b/app/control.js
@@ -149,8 +149,9 @@ function determinSwitchStatusByGridUsage(currentStatusValues, onStatusFunction,
     // check if enough solar power is available
     //console.log(new Date(), "Current status values", currentStatusValues)
     if (currentStatusValues.wattGridUsageLast < CONFIG.wattThresholdToSwitchOff && currentStatusValues.switchOn && 
-            Math.abs(currentStatusValues.wattGridUsageLast) >= CONFIG.wattThresholdToSwitchOff) {
-        // as long some energy is feed in keep it on
+            // shift the feed in energy by the watt threshold for switching off
+            Math.abs(currentStatusValues.wattGridUsageLast - CONFIG.wattThresholdToSwitchOff) >= 0) {
+        // as long as engergy usage is within defined limits (feed in or maybe low consumption) keep on
         return onStatusFunction(currentStatusValues);
     } else if (currentStatusValues.wattGridUsageLast < CONFIG.wattThresholdToSwitchOff && !currentStatusValues.switchOn &&
                 Math.abs(currentStatusValues.wattGridUsageLast) >= CONFIG.wattThresholdToSwitchOn &&
diff --git a/test/control.test.js b/test/control.test.js
index b422453..ad448c9 100644
--- a/test/control.test.js
+++ b/test/control.test.js
@@ -119,6 +119,17 @@ assertMeanLast(excessEnergyUnderThreshold + CONFIG.wattThresholdToSwitchOn, exce
 assertMeanLast(excessEnergyUnderThreshold + CONFIG.wattThresholdToSwitchOn*2, excessEnergyUnderThreshold + CONFIG.wattThresholdToSwitchOn*2, CONFIG.maxWaterTemperatureFallback - 1, SWITCH_STATUS.OFF_FORECAST, true, CONFIG.wattThresholdToSwitchOn - 10, new Date("2023-08-29T11:00:00Z"))
 assertMeanLast(excessEnergyUnderThreshold + CONFIG.wattThresholdToSwitchOn*2, excessEnergyUnderThreshold + CONFIG.wattThresholdToSwitchOn*2, CONFIG.maxWaterTemperatureFallback - CONFIG.maxWaterTemperatureDelta- 1, SWITCH_STATUS.OFF_FORECAST, true, CONFIG.wattThresholdToSwitchOn - 10, new Date("2023-08-29T11:00:00Z"))
 
+// check modified CONFIG.wattThresholdToSwitchOff value
+CONFIG.wattThresholdToSwitchOff=100
+assertMeanLast(excessEnergyOverThreshold, -101, minWaterTemperature +1, SWITCH_STATUS.ON_ENERGY, true)
+assertMeanLast(excessEnergyOverThreshold, 99, minWaterTemperature +1, SWITCH_STATUS.ON_ENERGY, true)
+assertMeanLast(excessEnergyOverThreshold, 100, minWaterTemperature +1, SWITCH_STATUS.OFF_LOW_ENERGY, true)
+
+assertMeanLast(excessEnergyOverThreshold, 100, minWaterTemperature +1, SWITCH_STATUS.OFF_LOW_ENERGY, false)
+assertMeanLast(excessEnergyOverThreshold, 99, minWaterTemperature +1, SWITCH_STATUS.OFF_LOW_ENERGY, false)
+assertMeanLast(excessEnergyOverThreshold, excessEnergyOverThreshold, minWaterTemperature +1, SWITCH_STATUS.ON_ENERGY, false)
+
+CONFIG.wattThresholdToSwitchOff=0
 
 // fallback to always off
 CONFIG.startHourFallback = 24