diff -r f84501d8dd87 -r 045db83dd013 brewco/simulator.c
--- a/brewco/simulator.c	Sat Dec 12 19:31:35 2015 +0100
+++ b/brewco/simulator.c	Sat Dec 12 21:20:46 2015 +0100
@@ -31,6 +31,7 @@
 
 int			SIM_hlt_value = 0;
 int			SIM_mlt_value = 0;
+int			SIM_cooler = FALSE;
 
 
 #ifdef HAVE_WIRINGPI_H
@@ -80,13 +81,20 @@
 	if (SIM_hlt_value) {
 	    Config.simulator->hlt_heater_temp += (250 - Config.simulator->hlt_heater_temp) / 2000;
 	} else {
-	    Config.simulator->hlt_heater_temp -= (Config.simulator->hlt_heater_temp - Config.simulator->hlt_temperature) / 1000;
+	    Config.simulator->hlt_heater_temp -= (Config.simulator->hlt_heater_temp - Config.simulator->hlt_temperature) / 500;
 	}
 	Config.simulator->mlt_heater_state = SIM_mlt_value;
 	if (SIM_mlt_value) {
 	    Config.simulator->mlt_heater_temp += (250 - Config.simulator->mlt_heater_temp) / 2000;
 	} else {
-	    Config.simulator->mlt_heater_temp -= (Config.simulator->mlt_heater_temp - Config.simulator->mlt_temperature) / 1000;
+	    Config.simulator->mlt_heater_temp -= (Config.simulator->mlt_heater_temp - Config.simulator->mlt_temperature) / 500;
+	}
+
+	/*
+	 * If cooling, bring down the MLT temperature. Assume 14 degrees coolwater.
+	 */
+	if (SIM_cooler) {
+	    Config.simulator->mlt_temperature -= (Config.simulator->mlt_temperature - 14) / (250 * Config.simulator->hlt_heater_volume);
 	}
 
 	/*
@@ -108,10 +116,10 @@
 	     * Each second
 	     */
 	    if (debug)
-		fprintf(stdout, "HLT temp=%f plate=%f val=%d   MLT temp=%f plate=%f val=%d   Room %.1f loops=%d\n",
+		fprintf(stdout, "HLT temp=%f plate=%f val=%d   MLT temp=%f plate=%f val=%d   Room %.1f loops=%d  cool=%s\n",
 			Config.simulator->hlt_temperature, Config.simulator->hlt_heater_temp, Config.simulator->hlt_heater_state,
 			Config.simulator->mlt_temperature, Config.simulator->mlt_heater_temp, Config.simulator->mlt_heater_state,
-			Config.simulator->room_temperature, loops);
+			Config.simulator->room_temperature, loops, SIM_cooler ? "Yes":"No");
 	    loops = 0;
 	}
 	usleep(50000);