diff -r b9130db48c63 -r ac27038f4c70 thermferm/server.c
--- a/thermferm/server.c	Tue Jun 02 14:14:20 2015 +0200
+++ b/thermferm/server.c	Tue Jun 02 17:13:13 2015 +0200
@@ -131,10 +131,12 @@
 	 */
 	fromlen = sizeof(peeraddr_in);
 	ret = recvfrom(s, &buf, 1, 0, (struct sockaddr *)&peeraddr_in, &fromlen);
-	if (ret < 1) {
+	if (ret < 0) {
 	    syslog(LOG_NOTICE, "recvfrom(): %s", strerror(errno));
-	    srv_send((char *)"518 recfrom(): %s", strerror(errno));
 	    return -1;	/* error */
+	} else if (ret == 0) {
+	    syslog(LOG_NOTICE, "recvfrom(): no-data");
+	    return -1;	/* no data */
 	}
 
 	if (buf == '\n')