Maytag MDG4000BWW dryer Parts

Maytag Neptune dryers are typically in the full-size class at about 6.0 cubic feet. If you are asking about your Maytag MDG4000BWW, that model is not a Neptune-series dryer; use the specs and dimensions in the MDG4000BWW installation guide to confirm the exact capacity for your specific dryer.

Typical capacity you will see (Neptune vs. other Maytag full-size dryers)

Neptune is a product line name, but capacity is mainly tied to whether the dryer is full-size or compact.

• Most full-size Maytag dryers (including many Neptune models) run around 6.0 cu. ft.
• Compact dryers are usually around 3.4 to 4.0 cu. ft.
• If your dryer handles comforters and large towel loads easily, it is almost always full-size

Dryer category	Typical capacity	What it means for loads
Full-size Maytag (many Neptune models)	~6.0 cu. ft.	Bedding, towels, mixed loads
Compact dryer	~3.4 to 4.0 cu. ft.	Smaller loads, tight spaces

How to confirm capacity for MDG4000BWW

We recommend using the model tag and installation documentation so you match the correct configuration.

• Verify the full model number on the dryer label: MDG4000BWW
• In the MDG4000BWW installation guide, check sections labeled Specifications, Dimensions, or Features
• If you are comparing dryers, use the table above to estimate load size while you confirm the exact spec

Why it matters

Drum capacity affects how much laundry you can dry efficiently. Overloading restricts airflow, increases dry time, and can make a full-size dryer perform like a smaller-capacity unit.

Related tip: airflow issues can mimic “too small” capacity

If normal loads take too long, fix airflow first.

• Clean the lint screen every load
• Check the vent duct for kinks, crushing, or lint buildup
• Replace a damaged or warped lint screen with the dryer lint filter WP33001808

Last updated: February 2026

A Maytag dryer typically lasts 13 years with normal household use and basic maintenance. For your Maytag MDG4000BWW, keeping airflow strong (clean lint system and venting) and fixing small issues early helps you reach that expected lifespan.

Typical life expectancy (what to expect)

Most residential dryers fall into a similar range; usage and ventilation make the biggest difference.

Dryer use pattern	Typical lifespan	What shortens it fastest
Light (1 to 3 loads/week)	14 to 16 years	Long, restricted venting
Average (4 to 7 loads/week)	12 to 14 years	Overloading, poor airflow
Heavy (8+ loads/week)	9 to 12 years	Heat stress, worn drum support parts

Maintenance that extends dryer life

These steps reduce heat stress on the motor, drum support, and gas burner system.

• Clean the lint screen every load; replace a damaged filter such as the dryer lint filter WP33001808.
• Check and clean the vent path regularly (dryer outlet to exterior hood).
• Avoid overloading; heavy loads strain the drum bearings and blower.
• Listen for squealing or rumbling; address drum support wear early.
• Keep the dryer level to reduce vibration and uneven drum wear.

Signs your dryer is nearing end-of-life (or needs key parts)

Some symptoms are simple maintenance; others point to common wear parts.

• Long dry times: usually restricted venting or a weak airflow component.
• No heat or intermittent heat (gas models): often ignition or gas valve component issues (for example, gas igniter 4391996 or gas sensor WP338906).
• Loud thumping or scraping: drum support or seal wear (for example, dryer drum bearing kit 306508 or dryer drum rear seal WP33001807).
• Burning smell: lint buildup or airflow restriction; stop using until cleaned.

Why it matters

A dryer that runs hot because of poor airflow wears out faster and can damage major components like the motor, blower wheel, and (on gas models) the ignition system. Your installation guide includes key installation and safety requirements that support proper operation.

Last updated: February 2026

If your Maytag dryer model MDG4000BWW runs but clothes stay damp, the most common causes are restricted exhaust airflow, poor make-up air in the laundry area, or a gas-heat ignition problem (igniter, radiant sensor, or gas valve coils). Start with venting and airflow checks first.

Quick checks that fix most “not drying” complaints

• Clean the lint screen and confirm it is not coated with fabric softener residue.
• Check the vent hood outside; make sure the flap opens strongly while the dryer runs.
• Inspect the entire exhaust duct for kinks, crushing, lint buildup, or long runs.
• Make sure the room has adequate make-up air and the dryer area is not blocking combustion or ventilation airflow (important for gas models).
• Verify the dryer is installed with proper clearances and the exhaust route matches the factory rear-exhaust setup unless an accessory exhaust kit was used.

For installation and venting requirements specific to this model, use the installation guide.

If it is a gas dryer: common heat-system causes

When airflow is good but there is still no heat (or heat starts then stops), these parts are frequent culprits on gas dryers:

• Gas igniter: can glow weakly or fail to ignite gas.
• Radiant (flame) sensor: can fail to detect heat and stop the gas valve from opening.
• Gas valve coils: can work when cold, then fail as they warm up.

Parts on this model page that match those symptoms:

• Gas igniter 4391996
• Gas sensor WP338906
• Second coil 279834

Symptom-to-likely-cause guide

What you notice	Most likely cause	What to do next
Dryer takes much longer than normal	Vent restriction or crushed duct	Shorten/straighten duct; clean venting
Clothes dry unevenly, loads feel hot	Poor airflow or overloaded drum	Reduce load size; confirm strong exhaust
No heat at all, drum tumbles	Ignition system issue	Check igniter/sensor/coils
Heat starts then quits mid-cycle	Gas valve coils failing hot	Replace coil kit

Why it matters

A dryer depends on steady airflow to carry moisture out. On gas models, the burner also needs adequate combustion air; blocked ventilation or poor make-up air can reduce heat and drying performance, even when the dryer seems to run normally.

Last updated: February 2026