Heating Element Ohms Good But No Heat: Why The Reading Misleads

Why this matters

A resistive heating element that ohms out correctly is the most over-trusted reading in no-heat diagnostics. The tech reads the bake element at the expected resistance, declares it good, and chases the control board for hours. But a static resistance check only proves the element is electrically continuous at low current. It says nothing about whether the element draws full current under load, whether it gets the voltage it needs, or whether it opens when hot. An element can read perfect cold and still produce no heat in service. This tree explains exactly why a good ohm reading misleads and how to confirm heat output the right way.

Symptom presentation

The appliance powers up, the control accepts the setting, but the cavity or drum never gets hot. On an electric oven the bake or broil element stays dark. On an electric dryer the drum tumbles with cold air. Resistance across the element measures in the normal band: roughly 10 to 40 ohms for an oven bake element, roughly 8 to 12 ohms for a 5000 W dryer coil. By that number the element looks healthy, so the no-heat complaint gets blamed on the board, the sensor, or the thermostat.

Quick checks

Confirm the appliance is actually calling for heat. Verify the cycle is in a heated mode, not air-fluff or proof. Confirm the door switch is made and the appliance is not in a delayed start. On a dryer, confirm both legs of the 240 V supply are present at the cord and that a tripped breaker leg is not the cause. On an oven, confirm the element terminals are not arced, loose, or burned at the connector.

Then measure resistance as a baseline only. A reading in spec tells you the element is not open. It is the floor of the diagnosis, never the ceiling.

Why the good reading misleads

Resistance is measured with the ohmmeter's tiny internal current, milliamps at most. Heat output depends on the element drawing tens of amps under full line voltage. The two conditions diverge in several real failures:

• Missing voltage. A 240 V element that ohms perfectly produces no heat if it only receives 120 V because one supply leg is dead. Half the voltage means a quarter of the power. The element reads good and barely warms.
• High-resistance connections upstream. A corroded terminal, a loose push-on, or a heat-damaged wire nut adds series resistance that the ohmmeter at the element terminals never sees. Under 30 A load that bad joint drops most of the voltage and the element starves.
• Open safety in series. A blown thermal fuse, an open high-limit thermostat, or an open cycling thermostat kills the circuit. The element itself still ohms fine when isolated; the dead component is in series, not in the element.
• Element opens hot. A coil with a hairline break can be continuous when cold and contracted, then open as it heats and expands. Cold ohms read good; the circuit dies seconds after the call for heat.
• Open neutral or ground reference. On some control schemes a missing reference path stops switching even though every component ohms out.

In every case the element is innocent and the ohmmeter reported only that one part is not open.

Isolation tree

Work the circuit under power, not just on the bench.

1. Confirm supply voltage at the appliance. Dryer: measure leg-to-leg at the terminal block; you need full 240 V (or per nameplate). Oven: confirm both legs feed the element relay. A missing leg is the most common cause of element ohms good, no heat.

2. Voltage present, element cold, call for heat active. Measure voltage directly across the element terminals while it should be energized:

   • Full voltage across element, no current, no heat. The element opens under load. Replace it.
   • No voltage across element. The break is upstream. Walk the series circuit.

3. No voltage across element, supply good. Check each series device while calling for heat: thermal fuse, high-limit, cycling thermostat, control relay, sensor circuit. Measure voltage drop across each. The device dropping the full line voltage is the open one.

4. Low voltage across element (half or partial). Suspect a high-resistance connection or a dead supply leg. Inspect and re-terminate corroded joints; confirm both legs at the source.

Confirming diagnosis

The definitive test is a current measurement under load. Clamp an ammeter on the element leg and call for heat:

• An oven bake element should draw roughly 12 to 16 A on 240 V (about 3000 to 3800 W).
• A dryer element should draw roughly 20 to 25 A on 240 V (about 5000 W).
• A dishwasher heater draws roughly 5 to 9 A.

Zero current with voltage present across the terminals confirms the element opens under load even though it ohmed good cold. Half the expected current confirms a voltage shortfall: trace it to a dead leg or a series resistance. Full expected current with no temperature rise points to a thermostat or sensing fault downstream, not the element.

Remediation

• Element opens under load: Replace the element. Re-test current draw after install.
• Dead supply leg: Repair the branch circuit, breaker, or terminal block. A burned dryer terminal block is common; replace it, not just the cord.
• High-resistance connection: Cut back damaged wire to clean copper, use high-temp porcelain or ceramic connectors rated for the location, and re-terminate.
• Open series safety: Replace the blown thermal fuse or open thermostat, and find why it opened (restricted dryer vent, failed cooling fan) so it does not blow again.

References

• UL 858, Standard for Household Electric Ranges
• UL 2158, Standard for Electric Clothes Dryers
• NFPA 70 (National Electrical Code), Article 422 Appliances and Article 250 Grounding
• DOE, 10 CFR Part 430 Subpart B, energy conservation test procedures for cooking products and clothes dryers