diff -r b73490398368 -r 8c7d87a2c094 thermferm/rdconfig.c
--- a/thermferm/rdconfig.c	Sun Aug 03 22:49:33 2014 +0200
+++ b/thermferm/rdconfig.c	Mon Aug 04 15:18:29 2014 +0200
@@ -680,6 +680,7 @@
     unit->idle_rangeH = 1.0;
     unit->idle_rangeL = -1.0;
     unit->prof_started = (time_t)0;
+    unit->PID_err_old = 0.0;
 
     cur = cur->xmlChildrenNode;
     while (cur != NULL) {