Furnace Fan Limit Switch Sticking

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Furnace fan limit switch sticking.

The fan limit switch tells the blower assembly when it is ok to blow the heated air. Limit switch issue furnace blower fan wont turn off if the furnace overheats then a limit switch will open. It should be located near the top of the furnace within the panel. Check to make sure the fan is not in the fan on position on your thermostat.

Look for the fan limit control switch encased in a small rectangular box. Set the temperature on the middle component to approximately 105 to 115 degrees fahrenheit. Setting the middle arm at this temperature ensures that the fan will switch on at the correct time when the furnace warms ups. Free shipping by amazon.

Follow the basic rules and replace it with an exact replacement. If your furnace goes off on high limit or if one of the rollout switches are open then the furnace fan will run all the time because the furnace control board is telling the furnace that the furnace has over heated and the fan runs to cool the furnace down. 11 thoughts on test and replace the fan limit switch on a furnace barney july 20 2020. Step 3 slide the cover off the control switch or lift it up.

So when the switch is working correctly your furnace fan should turn on several minutes after thermostat calls for heat and turn off several minutes after the heat cycle ends. Get it as soon as wed sep 30. Step 6 set the arm to left of the middle component to approximately 90 degrees fahrenheit. With the fan limit control it is possible it could also be sticking and needs replacing.

Once the fan limit switch has sensed that the air in the plenum is a suitable temperature usually around 20 degrees above the room temperature it engages the blower fan to distribute air. Either way something is sticking when it should not be stocking and the device needs to be replaced to correct the problem. My furnace fan stays on even after the furnace has cooled off until i bang the furnace cover then it goes off is that the fan limit switch sticking on. Honeywell l4064b2236 combination fan and limit furnace control.

Furnace temperature fan limit switch wiring diagram sample illustration for safety circuit. More buying choices 94 99 2 used new offers nordyne 626494r fan limit switch. The fan limit switch is responsible for turning the blower on and off at the appropriate times. Fan limit switch moves past fan off then past fan on blower doesn t start until about 10 20 degrees above fan on then blower runs on for 30 seconds and shuts off for a few minutes turns back on for 30 seconds and shuts off for a few minutes.