Joel Crawford
Sep. 18th, 2025
3 min read
Lately we’ve notice an uptick in reports of machines triggering their own reset, despite having an active flame in the burn chamber. The only way for a machine to go into reset is for the burner to be operating while the cad cell is not “sensing” a flame.
If your machine appears to operating normally while continually entering lockout there are two possible causes.
We have found that in most cases, the factory air shutter plate setting is the optimal position, but variances in fuel weights and temperatures sometimes require a slight deviation.
The Air Shutter can be found on the Compressor side of your burner, with a pointer aimed at the main body. The main body of your burner has numbers cast into the side, where this pointer is located.
Adjustments to the Air Shutter Plate should be made while the machine is running, in very small increments , in order to achieve the brightest, most stable burn possible- which can be verified visually through the view port on your burner, or by measuring the resistance across the cad cell leads. Using an ohm meter on the cad cell, your reading should be under 1600 ohms while the burner is operating. The lower the ohm reading, the brighter the flame.
The gallery below shows a sequence of pictures, taken as the air shutter was adjusted. Starting with the top left you can see the flame is weak as the air shutter is closed down, and the flame gets brighter and brighter as the Air Shutter Plate opens and approaches its best adjustment. In this case, we’re looking at an EL200H and the best setting turned out to be the factory setting of 7.
Factory Recommended Air Shutter Plate settings are as follows:
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