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Replacement parts for WHIRLPOOL RED4440SQ0 29``ELECTRIC DRYER | AppliancePartsPros.com

First thing to check is the power. The motor etc. uses 120 volts (half the line) while the heating coil requires the full 240 volts.

Try flipping the breaker off/on slowly a couple times, sometimes you can loose half the line without actually tripping the breaker.
If this does nothing, check the voltage at the plug
L1 to L2 should be 240 volts
L1 to Neutral and L2 to Neutral, both should be 120 volts.
If OK
Unplug the unit and check the wires at the terminal strip in the machine to make sure none are loose or burned out
If OK
Check the power at the terminal strip.
[COLOR="Red"]Be careful as 240 volts is lethal !!! [/COLOR]

Next would be the heating coil. Should be 10 to 12 ohms.

Then the heater's thermal cut-off (Item 9 in Section 3). It should be 0 ohms.
If it is blown then there are other things you should check before replacing it.