Dryer No Heat - Decision Tree (Electric)

Why this matters

An electric dryer that tumbles but does not heat covers six root causes, three of which share a symptom (no heat, no error code) and three of which present with subtle differences a careful diagnostic technician can use to skip steps. Failing to walk the tree wastes the customer's time and the company's parts budget - the heating element is the most expensive single part and is often replaced when the actual failure is a $12 thermal fuse. This article gives you the multimeter sequence to land on the correct part the first time.

Symptom definition

"No heat" means the drum tumbles, the timer advances, the cycle completes, and the load is still wet and cold at the end. Confirm the symptom before diagnosing:

• Cycle does NOT show an error code on the display.
• Drum tumbles normally.
• No burning smell, no smoke.
• Vent airflow at the wall outlet is present (if absent, suspect lint trap or vent obstruction first).

If the drum does not tumble, exit this tree - the motor or door switch is the suspect, not the heating circuit.

Step 1 - Verify both legs of 240 V power

An electric dryer requires 240 V to the heating element and 120 V to the motor and controls, supplied by a 240 V outlet with two hot legs. A single lost hot leg leaves the motor running on its 120 V leg but produces zero heat.

Diagnostic: at the dryer's outlet (with the appliance unplugged), use a multimeter to measure leg-to-leg (240 V), leg-1-to-neutral (120 V), leg-2-to-neutral (120 V). If any reading is 0 V, the breaker has tripped one leg or a wire is loose at the breaker. Refer to the electrician; do not attempt panel work without licensure. Re-test after the panel is corrected.

This is the #1 cause when the customer reports the failure started suddenly with no warning - typically a partially-tripped breaker after a household power blip.

Step 2 - Inspect the lint trap and exhaust vent

A clogged exhaust vent overheats the air in the heater housing, and the dryer's safety thermostat trips to protect the cabinet. The trip resets when the dryer cools, so the customer experiences "intermittent no heat" before "no heat at all" once the thermal fuse permanently opens.

Diagnostic: pull the lint trap and check for visible buildup. Disconnect the dryer's flex duct at the wall outlet and run a brush through the full exhaust path. Run the dryer with the duct disconnected and feel the exhaust air at the back of the unit - it should be warm-to-hot within 2 minutes of cycle start.

If the cause was a blocked vent, the thermal fuse may already be open. Do not skip Step 3.

Step 3 - Test the thermal fuse

The thermal fuse is a one-time-use safety device on the blower housing or heater housing. It opens at a specific over-temperature (typically 196 F for most US-market dryers) and does not reset. If the vent has been historically restricted, the fuse will be open. Replacing the fuse without fixing the vent guarantees the new fuse opens within hours.

Diagnostic: unplug the dryer. Locate the thermal fuse per the model-specific service manual (typically blower housing on Whirlpool, heater housing on GE). Probe with a multimeter set to continuity. An intact fuse reads zero ohms (continuity); an open fuse reads OL (infinity). Replace with the OEM-spec part - aftermarket fuses with the wrong trip temperature will either nuisance-trip or fail to protect.

Step 4 - Test the high-limit thermostat

The high-limit thermostat is a resettable device (in some models) that opens at over-temperature, similar to the thermal fuse but with auto-reset. A failed high-limit thermostat stuck open kills heat permanently; a high-limit that resets but is set too low causes the dryer to oscillate between heat and no-heat.

Diagnostic: probe the high-limit with a multimeter set to continuity. Cold, it should read zero ohms. If open at room temperature, replace. Inspect for signs of historic overheating (discoloration, melted insulation) which indicates the underlying cause is vent restriction or blower motor failure.

Step 5 - Test the cycling thermostat

The cycling thermostat opens and closes during normal operation to maintain drum temperature. A failed cycling thermostat stuck open kills heat. A failed cycling thermostat stuck closed overheats but typically trips the high-limit before damage.

Diagnostic: at room temperature, the cycling thermostat reads zero ohms (continuity). If open at room temperature, replace.

Step 6 - Test the heating element

The heating element is a coiled resistance wire inside a metal can on the back or bottom of the appliance, drawing 240 V across the full element. A break anywhere along the coil opens the circuit and produces no heat.

Diagnostic: disconnect the element's two terminals. Probe element-to-element with multimeter set to ohms. A healthy heating element measures 8 to 15 ohms (model-specific - consult service manual). An open element reads OL. Probe element-to-chassis - a healthy element reads infinity; a shorted element reads low resistance and is a shock hazard, replace immediately and inspect for cause.

Step 7 - Test the timer or control board

If Steps 1 through 6 are all healthy, the timer or electronic control board is not supplying the heater circuit during the cycle. This is rare but possible.

Diagnostic: with the dryer in a heated cycle and the heating element disconnected, probe the supply leads to the element with a multimeter set to AC volts. You should see 240 V. If absent, trace the control circuit back through the timer or board per the service manual. Replace the timer or board as the schematic indicates.

Decision summary

Pareto distribution across documented service calls:

• Vent restriction (with or without thermal fuse open): 35%
• Thermal fuse open: 25% (correlated with vent)
• Heating element open: 20%
• Cycling thermostat: 10%
• High-limit thermostat: 5%
• Power supply issue (breaker, outlet): 3%
• Timer/control board: 2%

Always address the vent before replacing parts. A new heating element installed without fixing the underlying vent restriction has a service life of weeks, not years.

References

• Whirlpool Corporation, Service Manual W11042730 Electric Dryer Diagnostics.
• GE Appliances Technical Service Bulletin DR-008, Heating Circuit Troubleshooting.
• NEC 422 Article 422.10, Branch Circuit Requirements for Appliances.
• NFPA 70 National Electrical Code 2023, Article 422 Appliance Wiring.
• ANSI/UL 2158, Standard for Electric Clothes Dryers.