BEC

I had a high pitched buzzing noise coming from my furnace room.  I was not sure if it came from my electric furnace or my propane furnace or from the converter that changes them back and forth when I am rippled.  I called BEC and a technician came out very quickly as they thought it was probably a dangerous situation.  We come to find out that on my electric furnace I have a sensor that will emit a high pitched tone when the furnace is overheating and the walls and the rest of the ducting can not cool off.  The problem was due to the filter as it was  restricting air  hence it could not cool down.  The sensor would send the alarm and shut off the furnace.  He pulled the filter and showed me that it actually fixed the problem.  He told me to go buy a less restrictive filter.  So off  I went after knitting and found the task troubling.  First,  I looked at construction of the filters offered.  Then I looked at price.  I finally chose by price.  I found filter that cost 2 dollars for four filters.  I knew I had come across the least restrictive filters.  All is working well.