diff -r dc88583a068d -r df81d583c2c3 thermferm/thermferm.c
--- a/thermferm/thermferm.c	Tue Aug 26 14:45:03 2014 +0200
+++ b/thermferm/thermferm.c	Sat Aug 30 13:06:07 2014 +0200
@@ -252,6 +252,7 @@
     /* Allways turn everything off after a mode change */
     current_unit->PID_I_err = current_unit->PID_err_old = 0.0;
     current_unit->heater_state = current_unit->cooler_state = current_unit->fan_state = 0;
+    current_unit->heater_wait = current_unit->cooler_wait = current_unit->fan_wait = 0;
     device_out(current_unit->heater_address, current_unit->heater_state);
     device_out(current_unit->cooler_address, current_unit->cooler_state);
     device_out(current_unit->fan_address, current_unit->fan_state);
@@ -915,6 +916,7 @@
 	 * Safety, turn everything off
 	 */
 	unit->heater_state = unit->cooler_state = unit->fan_state = unit->door_state = 0;
+	unit->heater_wait = unit->cooler_wait = unit->fan_wait = 0;
 	if (unit->mode == UNITMODE_PROFILE) {
 	    if (!unit->profile)
 		syslog(LOG_NOTICE, "Starting unit %s in profile mode, no profile defined.", unit->name);
@@ -1285,26 +1287,43 @@
 					sp, pv, unit->PID_err_old, err, P_err, unit->PID_I_err, D_err, Out);
 			}
 			if (unit->heater_address) {
-			    if (Out >= 2) {
-				if (! unit->heater_state)
-				    syslog(LOG_NOTICE, "Heater Off => On");
-				unit->heater_state = 100;
+			    if (unit->heater_wait < unit->heater_delay) {
+				unit->heater_wait++;
+				syslog(LOG_NOTICE, "heater_wait %d/%d", unit->heater_wait, unit->heater_delay);
 			    } else {
-				if (unit->heater_state)
-				    syslog(LOG_NOTICE, "Heater On => Off");
-				unit->heater_state = 0;
+			        if (Out >= 2) {
+				    if (! unit->heater_state && ! unit->cooler_state) {
+				    	syslog(LOG_NOTICE, "Heater Off => On");
+					unit->heater_wait = 0;
+				    	unit->heater_state = 100;
+				    }
+			    	} else {
+				    if (unit->heater_state) {
+				    	syslog(LOG_NOTICE, "Heater On => Off");
+					unit->heater_wait = 0;
+				    	unit->heater_state = 0;
+				    }
+			    	}
 			    }
 			    device_out(unit->heater_address, unit->heater_state);
 			}
 			if (unit->cooler_address) {
-			    if (Out <= -2) {
-				if (! unit->cooler_state)
-				    syslog(LOG_NOTICE, "Cooler Off => On");
-				unit->cooler_state = 100;
+			    if (unit->cooler_wait < unit->cooler_delay) {
+				unit->cooler_wait++;
 			    } else {
-				if (unit->cooler_state)
-				    syslog(LOG_NOTICE, "Cooler On => Off");
-				unit->cooler_state = 0;
+			    	if (Out <= -2) {
+				    if (! unit->cooler_state && ! unit->heater_state) {
+				    	syslog(LOG_NOTICE, "Cooler Off => On");
+					unit->cooler_wait = 0;
+					unit->cooler_state = 100;
+				    }
+			    	} else {
+				    if (unit->cooler_state) {
+				    	syslog(LOG_NOTICE, "Cooler On => Off");
+					unit->cooler_wait = 0;
+					unit->cooler_state = 0;
+				    }
+				}
 			    }
 			    device_out(unit->cooler_address, unit->cooler_state);
 			}
@@ -1422,6 +1441,7 @@
 	 * Turn everything off
 	 */
 	unit->heater_state = unit->cooler_state = unit->fan_state = unit->door_state = 0;
+	unit->heater_wait = unit->cooler_wait = unit->fan_wait = 0;
 	device_out(unit->heater_address, unit->heater_state);
 	device_out(unit->cooler_address, unit->cooler_state);
 	device_out(unit->fan_address, unit->fan_state);