diff --git a/inc/temp.inc.sh b/inc/temp.inc.sh
index 35eb1b1f..25b1de25 100644
--- a/inc/temp.inc.sh
+++ b/inc/temp.inc.sh
@@ -482,11 +482,13 @@ Previous Temp: ${last_temp[${SENSOR//-/}]}${GAUGESH}"
 							#### LOGGING OF SERVERROOM SENSOR DIFFERENCE
 							if [ "${SENSOR}" == "ServerRoomLA" ]; then
 								if [ ! -f ${PW_TMPFOLDER}/.log.sr.difference ] || [ $(expr `date +%s` - $(stat -c %Y ${PW_TMPFOLDER}/.log.sr.difference)) -ge 10 ]; then
-									[ ! -f ${PW_TMPFOLDER}/.log.sr.difference ] && touch ${PW_TMPFOLDER}/.log.sr.difference
-									temp_difference=$(bc <<< "scale=1; ${temp_probe_f}-${ServerRoomTH}")
-									(( $(bc <<<"${temp_difference} < 0") )) && temp_difference=`echo "scale=1; ${temp_difference} * -1" | bc`
-									echo "HERE: ${temp_probe_f} - ${ServerRoomTH} = ${temp_difference}"
-									echo ${temp_difference} >> ${PW_TMPFOLDER}/.log.sr.difference
+									if [ "${temp_probe_f}" != "" ] && [ "${ServerRoomTH}" != "" ]; then
+										[ ! -f ${PW_TMPFOLDER}/.log.sr.difference ] && touch ${PW_TMPFOLDER}/.log.sr.difference
+										temp_difference=$(bc <<< "scale=1; ${temp_probe_f}-${ServerRoomTH}")
+										(( $(bc <<<"${temp_difference} < 0") )) && temp_difference=`echo "scale=1; ${temp_difference} * -1" | bc`
+										echo "HERE: ${temp_probe_f} - ${ServerRoomTH} = ${temp_difference}"
+										echo ${temp_difference} >> ${PW_TMPFOLDER}/.log.sr.difference
+									fi
 								fi
 							elif [ "${SENSOR}" == "ServerRoomTH" ]; then
 								ServerRoomTH=${temp_f}