New Dryer No Heat At Installation Gas Vs Electric Decision Tree

Why this matters

A new dryer that tumbles but never heats is one of the highest-frequency install callbacks, and the root cause splits cleanly by fuel type. Electric dryers run the motor on 120 V but the heating element on 240 V; lose one leg and the drum spins with no heat and no fault. Gas dryers need the gas valve turned on, air bled, and the igniter circuit intact. Mislabeling a supply problem as a unit defect gets a good dryer swapped while the dead leg or the closed gas cock follows the replacement. The diagnosis has to separate the appliance from the supply before any warranty claim is filed.

Symptom presentation

Drum turns, air moves, timer counts down, but the clothes stay cold and the exhaust is room-temperature. First question on every call: gas or electric. The supply architecture and the entire isolation path differ. On electric, no heat with a running motor is the classic single-leg loss. On gas, the same symptom is usually gas not reaching or not igniting at the burner.

Quick checks

• Confirm fuel type and how the unit is supplied. Electric: 30 A, 120/240 V, 3- or 4-wire cord and matching receptacle. Gas: 120 V cord plus a gas line with a shutoff.
• Electric, no heat: this is a lost 240 V leg until proven otherwise. With power off, inspect the cord and the receptacle, then meter the receptacle for both legs.
• Gas, no heat: confirm the gas shutoff at the appliance is fully open and the line has been bled (a new connection is full of air; the first cycles may not light until air clears).
• Confirm the vent is connected and not crushed. A blocked vent can trip the thermal limit and cut heat, though a brand-new install with a clean run is more often supply or gas.
• Confirm the cycle selected actually calls for heat (Air Fluff / Air Dry runs no heat by design).

Isolation tree

Branch A: Electric, drum runs, no heat.

• Meter the receptacle: each hot leg to neutral should read about 120 V, and hot-to-hot about 240 V. One leg reading 0 and hot-to-hot reading ~120 V -> dead leg. Cause is a tripped/half-tripped double-pole breaker, a loose neutral, or a miswired receptacle. Not the appliance.
• Both legs good (240 V at the receptacle) but no heat -> open heating element, open thermal fuse/limit, or control. With power off, ohm the element (continuity expected) and the thermal fuse (continuity expected; open fuse means it tripped, usually on airflow). New-unit element or thermal failure is a warranty part.

Branch B: Gas, drum runs, no heat.

• Gas shutoff closed or line not bled -> open the valve, run several cycles to clear air. Resolved.
• Gas on and bled, igniter glows then no flame -> gas valve coils or the igniter dropping out before the valve opens. Confirm the igniter glows brightly and the valve clicks open. A coil set that glows but never opens is a warranty part on a new unit.
• Igniter does not glow at all -> open igniter, open thermal fuse, or control not calling. Ohm the igniter and thermal fuse with power off.

Branch C: Either fuel, intermittent or trips after minutes.

• Blocked/crushed vent -> thermal limit cuts heat. Clear the vent, confirm proper exhaust run, re-test.

Confirming diagnosis

Electric: the meter at the receptacle is the whole case. Two good legs plus no heat moves the fault into the appliance (element/thermal/control). One dead leg moves it to the supply (breaker, neutral, receptacle wiring). Document both readings. Gas: confirm the valve is open and the line bled, then watch one ignition sequence. Igniter glow plus no valve opening is a coil fault; no glow with a good thermal fuse is an igniter fault. Document the glow/valve behavior and the thermal-fuse continuity.

Remediation

• Electric dead leg: refer to electrician for breaker/neutral/receptacle correction; re-meter both legs after the fix.
• Electric element/thermal/control on a new unit: warranty part per manufacturer policy after confirming both legs are good.
• Gas closed/unbled: open valve, bleed line, run to clear air, leak-check the connection.
• Gas igniter or valve-coil fault: warranty part on a new unit; leak-check after any gas-side work.
• Blocked vent: correct the exhaust run, then re-verify heat and exhaust temperature.

Re-verify by running a heated cycle to completion and confirming rising exhaust temperature and dry clothes.

References

• NEC (NFPA 70), Article 250 and Article 422 - grounding, neutral, and 120/240 V appliance branch-circuit requirements for electric dryers.
• ANSI Z21.5.1 / CSA 7.1 - gas clothes dryers; connector and gas-train safety basis.
• UL 2158, Standard for Electric Clothes Dryers - construction and safety basis.
• AHAM - household dryer installation and venting guidance.