What is the draft reading for the over the fire draft test on an oil burner?

The draft reading for the over the fire draft test on an oil burner is measured in inches of water column (wc), indicating whether there's a positive or negative pressure relative to the atmospheric pressure. A negative draft reading indicates that there is a slight vacuum created at the fire zone, which is essential for controlling the combustion process effectively.

In the context of oil burners, a draft reading of -0.02"wc is typical and indicative of the proper operating conditions. This negative draft helps to ensure that combustion gases are efficiently evacuated from the combustion chamber and that fresh air is drawn into the burner, promoting effective and safe combustion.

When discussing why this specific draft reading is crucial, it is worth noting that maintaining the proper negative pressure is vital to prevent problems such as backdrafts, which can lead to inefficient burning or even hazardous situations. Therefore, in the operation and maintenance of oil burners, monitoring for this draft level is critical for optimal performance and safety.