Fan or heater not coming on - Heating & Cooling

What you describe is true for many home heaters, but maybe not true very often for cars. For most cars - especially older ones, the fan speed is independent of the engine temperature, and the heater will not "blow warm" until the engine has warmed up. There are also many new cars that let you set a temperature, and then automatically change the fan as appropriate. Those have many different behaviors, but in order for others to provide help I think it might be helpful if you said which model and year car you were asking about.

The fan is either bad or stuck, try moving the fan with a screw driver if you can see it. Do this while the heater is unplugged from power.

The cooling fan should come on when the coolant temp reaches around 200 degrees F. regardless of what position the heater switch is in.

The fan comes on when the defrost is on because the defrost automatically turns on the A/C. The A/C dries the incomming air to help clear the windshield.

I’m happy to assist further over the phone at https://www.6ya.com/expert/jeremy_d728a59f986299fa

Maybee the fan is 120v and the heater is 240v ? model number of the devicee would help

Are we sure it is the fan assembly or the outside cover? if not, are the fan blades bent or is the unit not level, causing some interference?

open it up and you'll see it while its running sounds like fan bearings or fan misalignment may need a new fan motor. if you replace the fan though make sure all power is off before disconnecting

Thed fan should come on soon after plugging in as long as the heater is cold. The heater then shuts off after sensing no flame. Either the wiring is bad, the fan motor is bad, of the top has been bent down so it is hitting the fan. Remove the top, make sure the fan turns freely and check power to the fan motor. The fan motor also turns the air pump that **** the ful out of the tank. Ck this and let me know if you need help.

Replace Fan or possibly thermostat module

it very well sounds like your fan switch , does your fan work at all, like in ac mode on by turning the fan on/auto switch on the thermostat to ON. If the fan does come on its the more and likely the limit switch. if it doesnt come on it could be the motor or the run capacitor. the limit switch has a dial on it that as it heats up it spins clicking on at a desired set temp ussually about 120 to 150 degrees F. turning on the fan if the fan doen't come in the the next setting clicks off the gas valve turning off the burners ussually set at about 220 degrees F. now if the fan is working when the heater is satisfied there is a setting at about 90 deegrees F. that shuts the fan off hope this helps

seems to me you have a bad bearing in the fan. if you can access the fan, have a few drops of oil poured on the shaft of the fan and see if it solves your prob.