The way to tell is by watching when the flame blows back... if it is venting it will be almost immediate and if it is a crack then it will happen when the blower comes on...The way to tell is by watching when the flame blows back... if it is venting it will be almost immediate and if it is a crack then it will happen when the blower comes on...
Answers & Comments
Hello,
Not sure what type of heating unit you have, but it sounds like either a cracked heat exchanger or you have a venting problem.
If the heat exchanger is cracked then the air from the blower will blow through the crack and blow the flame back...
If there is a venting problem, then the flame heat has no way to go so the heat will come back out and cause these problems...
Heatman101
The way to tell is by watching when the flame blows back... if it is venting it will be almost immediate and if it is a crack then it will happen when the blower comes on...