Re: Short fan cycle on oil furnace (different from other post)
The blower kicks on when the high limit is reached in the heat exchanger and shuts off when the low limit is reached. By adding additional returns you are supplying additional cold air cooling the heat exchanger.
You may be able to balance the system by adding baffles in the returns or, if the motor is multi speed, running the blower on a slower speed. Proper balance is necessary for proper function. You may also be able to change the nozzle for more heat but you'll use more fuel when it is running.
Last edited by JLMCDANIEL; 12-16-2009 at 06:15 PM.
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