Winter months are typical times to notice furnaces turning on and off several times for brief times. Then after attempting to turn on three times, there is a shutdown of the furnace for approximately one to two hours. The furnace tries starting up again after this waiting period. This problem may be caused from the flame sensor. It can possibly be bad or dirty. Furnaces that have not had maintenance or heating repair in past two to five years have this occurring often.
What Steps To Take With Dirty Flame Sensors
Flame sensors should be checked and cleaned by a service technician. Depending on what is causing the problem, it may need either replacing or only just a proper cleaning. Either one of these solutions should be a heating repair that is low cost. Homeowners should be sure to have annual maintenance tune-ups on their furnace, with a crucial part included being flame sensor checking and cleaning. This is not considered a DIY project but one that requires professional HVAC technicians.
Necessity of Flame Sensors in Furnaces
There are several safety features in gas furnaces, flame sensors are one of them. Some are checked prior to gas burning and others after gas burns. Ones which check after gas burns are for the purpose of protection of homes and individuals residing in them from hazardous conditions while furnace gas is burning. Flame sensors are made of metals that when in a presence of flames it creates an electrical current. They are designed to shut down the furnace if and when there is not enough burning fuel at the very last burner, is not detected. When a last burner in a group of burners has a steady flame, this shows there is a safe burning environment. If there is no flame present, then any burner in this group could be burning fuel unsafely. When no flame is detected during system check, the fuel valve is then shut down. Due to false readings that any system is capable of having, control boards make two more attempts to light the burners. If each of the three times a flame sensor does not detect a flame, a furnace is shut down for one to two hours or until a reset can be completed. Service technician needs to be called for heating repair when a reset is required.
When a flame sensor malfunctions, the most likely cause is dirt. Professional heating repair technicians are able to assist with this problem.
