Good Afternoon Not sure this is the right section for this question but will start here and move if you think there is a more suitable section for it. I have a garage workshop car repairer modern building it is fitted with a suspended from the ceiling Reznor Gas heater model UDSA043 This thing has performed faultlessly for 6 years since install, the last three months it has been behaving erratically, basically it wont start when the ambient temp in building is low, ie. below about 14 degrees. if the temp is above that it will start, we had someone have a look at it about two weeks ago, there was some wiring tidied up as the connection on some of the wiring blocks were slack etc It worked every morning till this morning, today was the first low temp day since the day the wiring was looked at, so it would appear the same problem exsist's So it looks like the wiring is not at fault as the same problem is still persisting. basically works when ambient room temp is reasonably high but will not work at all when temps are low. This is an odd one !!