DIAGNOSIS: No heat with normal spinning means the heating circuit is open. The prime suspects are the thermal fuse (a one-time safety cutoff) or the heating element itself could be broken.
FIX: Unplug the dryer. The thermal fuse is a small, white ceramic part with two wires, usually located on the heater housing or the exhaust duct near the back. Use a multimeter to test it for continuity (it should have zero resistance). If it's blown (open circuit), it needs replacement. This is a very common failure, especially if the vent was even slightly restricted.
IF THAT DIDN'T WORK: Next, test the heating element for continuity and also check that it's not grounded to the dryer cabinet (which would trip the thermal fuse). A visual inspection through the rear grill might show a broken coil.
HEADS UP: Replacing a blown thermal fuse without finding and fixing the cause (like a clogged vent) is a waste of time. It'll just blow again. Always clear the venting system completely when you replace a thermal fuse.