No heat
When a dryer tumbles but produces no heat, the problem is almost always in one of two systems: the heating circuit itself, or the safety circuit that shuts heat off when airflow is restricted. Understanding which system has failed is the fastest path to a fix. If the heating element or gas igniter has physically failed, the dryer simply can't produce heat — this is a component replacement. But if a thermal fuse or hi-limit thermostat has tripped, the heating circuit is intact — a safety device interrupted it because something else (usually a clogged exhaust vent) caused the dryer to overheat. Fixing the fuse without fixing the airflow problem means the fuse will blow again. This page covers both failure modes, the parts most commonly needed, and how to tell which system is the actual culprit.
Safety
Critical- Disconnect power before testing: Electric dryers operate on 240V circuits. Always unplug the dryer or turn off both circuit breakers before accessing any internal components.
- Gas leak awareness: If you smell gas at any point, stop immediately. Do not operate switches or create sparks. Leave the area and call your gas utility.
- Hot surfaces after operation: The heating element housing, exhaust duct, and surrounding components remain hot for several minutes after the dryer stops. Allow cooling time before touching.
- Check both breakers: Electric dryers use two breakers. If one trips, the drum may spin but the heating element won't energize. Check both breakers even if the dryer appears to run.
- Lint is a fire hazard: Accumulated lint in the exhaust duct is a leading cause of dryer fires. Clean the full vent path from the dryer to the exterior wall annually.
How to approach this
Start with the simplest checks first. Verify the dryer is set to a heated cycle (not air-dry or fluff). Check the lint filter and exhaust vent for blockages — restricted airflow is the single most common root cause of heating failures because it triggers the safety devices that cut heat. If airflow is clear, the next step depends on whether you have an electric or gas dryer. On electric models, test the heating element for continuity with a multimeter — but disconnect the element from its terminals first, because a shorted element can show continuity through the grounded cabinet and give you a false reading. On gas models, observe the igniter during a cycle — it should glow bright orange for 60-90 seconds before the gas valve opens. If the igniter glows but gas never flows, the gas valve coils are likely failing. If it doesn't glow at all, the igniter itself needs replacement.
Repair tips for this model
From OEM manual analysis for the DV42H
From the service manual
Good to know
5 technician insights for this model
Noisy dryer diagnosis — identify the sound type first
Different sounds point to different components: 'Thumping' = check loose tumbler baffle, rear roller(s) worn/misaligned, out-of-round tumbler or high weld seam. 'Ticking' = check loose wire harness or object in blower wheel area. 'Scraping' = check front/rear bulkhead felt seal out of position or worn tumbler front bearings. 'Roaring' = check blower wheel rubbing on housing or bad motor bearings. 'Popping/squealing' = check sticky or frayed belt. 'Whistling from door' = check door seal assembly condition and door lever.
Dropped screws recovery through duct exhaust hole
If screws for fixing the power cord are dropped into the dryer during service, they can be recovered through the duct exhaust hole. Remove the Duct Exhaust (1 screw from Back-Cover, 1 screw from Duct-Exhaust) and retrieve the dropped screw through the hole. This avoids a full disassembly just to retrieve a dropped fastener.
Gas model ignition sequence — three distinct failure symptoms
Gas modelsGas model ignition problems produce three distinct symptoms requiring different diagnosis: (1) Igniter does not glow = check flame sensor, igniter, booster coil, wiring, motor switch, control power. (2) Igniter glows but no gas ignition = check secondary coil, holding coil, wire harness, stuck flame sensor. (3) Gas ignites but flame goes out = check radiant sensor contacts, weak gas valve coil, weak Hi-Limit, poor venting, bad drum seals. Identifying which symptom is present dramatically narrows the diagnosis.
Static electricity precaution when handling PCBs
Electric modelsBefore touching or replacing any PCB (Main or Sub), you must discharge static electricity from your body by contacting the power plug first. Static electricity from the resin parts of the dryer or the human body can damage electronic components. This is explicitly required before any PCB work.
Common causes
Ordered by how frequently each component is involved, based on OEM manual analysis.
Heating element failure
Most commonThe heating element is a coiled wire that generates heat when electricity passes through it. Over time, the wire develops hot spots, weakens, and eventually breaks. When it breaks, the circuit opens and no heat is produced. This is the single most common cause of no-heat complaints on electric dryers.
Restricted exhaust vent
Most commonA partially or fully blocked exhaust vent is the most common root cause of dryer heating failures — not because it stops heat directly, but because it causes overheating that trips the thermal fuse or hi-limit thermostat. If you've replaced a thermal fuse and it blew again, the vent is almost certainly the underlying problem. Check the full run from the dryer to the exterior wall.
Blown thermal fuse
CommonThe thermal fuse is a one-time safety device that blows when the dryer overheats. Once blown, it breaks the heating circuit permanently. A blown fuse is almost never the primary failure — it's a symptom of restricted airflow or a failed cycling thermostat. Always find and fix the underlying cause before replacing the fuse, or it will blow again.
Faulty gas valve coils (gas models)
CommonGas dryers use electromagnetic coils to open the gas valve. These coils weaken with heat cycling over time. A classic symptom is intermittent heating — the dryer heats initially but stops mid-cycle as the coils fail to hold the valve open after repeated thermal cycling.
Defective cycling thermostat
CommonThe cycling thermostat regulates drum temperature by switching the heater on and off. If it fails in the open position, it permanently breaks the heating circuit. Test with a multimeter — it should show continuity at room temperature.
Broken igniter (gas models)
CommonThe igniter must reach approximately 1800°F to trigger the gas valve. A weak or cracked igniter won't reach this threshold. You can observe it during a cycle — if it glows but gas never ignites, the igniter has lost sufficient output. If it doesn't glow at all, it's open-circuit and needs replacement.
Verified Components
Parts
8Part numbers confirmed across multiple retailers for DV42H
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How we verify parts for your model. Parts shown are confirmed at multiple retailers specifically for the DV42H. Cross-referenced against OEM documentation.
About this content. Common causes and FAQs are generated from OEM manual analysis and verified parts data. This is general guidance - your specific model may have different components or access points. Always verify with your model's documentation before ordering parts.