Whirlpool WMH73L20AS0 2.0 cubic foot microwave/hood combo Parts

No. Your Whirlpool WMH73L20AS0 microwave/hood combo can be installed to vent air outside (wall or roof) or set up as a recirculating (non-vented) installation; the right choice depends on your kitchen layout and whether you have ductwork available. Use the installation guide to confirm the venting configuration and clearances.

Venting options for WMH73L20AS0

Most installations fall into one of these setups:

• Wall venting (outside): exhaust goes through the back wall to a wall cap
• Roof venting (outside): exhaust goes up through the cabinet and roof cap
• Recirculation (no outside vent): air is filtered and returned to the kitchen (no duct to outdoors)

When we recommend venting outside

Venting outdoors is the best performance option when you can run ductwork.

• Removes heat, smoke, and odors more effectively
• Helps reduce grease buildup in the kitchen
• Typically improves fan performance by reducing restriction
• Avoids sending moist air back into the room during heavy cooking

Key installation notes that affect venting

The vent path and cabinet space must allow the damper to open freely and the duct to fit correctly.

• Use a rigid metal vent when venting outside (flex vent is not recommended)
• Keep the duct run short and direct; minimize elbows
• Do not vent exhaust air into concealed spaces (walls, ceilings, attics, crawl spaces, garages)
• If using a rectangular-to-round transition for roof venting, maintain at least 3 inches of clearance above the microwave so the damper can open

Quick comparison: outside venting vs recirculation

Setup	Duct to outdoors	Odor removal	Typical best use
Wall venting	Yes	Best	Exterior wall behind microwave
Roof venting	Yes	Best	Duct run up through cabinet/roof
Recirculation	No	Good (depends on filters)	No practical duct route

Why it matters

Choosing the correct venting method protects cabinets and finishes from heat and grease, improves fan performance, and helps prevent installation issues like a stuck damper or restricted airflow.

For replacement parts that support safe operation (for example door safety switches), you can order model-matched parts from this page or search by model on Sears PartsDirect.

Last updated: February 2026

A Whirlpool microwave typically lasts 8 to 10 years. For a Whirlpool over-the-range microwave/hood combo like model WMH73L20AS0, lifespan depends most on daily run time, keeping airflow and filters clean, and avoiding repeated door slams that stress the interlock system.

What affects lifespan the most

• Ventilation and heat: Grease buildup and restricted airflow make components run hotter.
• Door use: Worn door switches and interlocks can stop heating or prevent starting.
• Power quality: Surges and repeated breaker trips shorten control and high-voltage component life.
• Cleaning habits: Steam and grease left inside can damage surfaces and sensors.
• Installation quality: Proper mounting and venting reduce vibration and heat stress (see the installation guide).

Maintenance that helps you reach the full 8 to 10 years

• Clean or replace the grease filter on schedule; a clogged filter makes the vent fan work harder.
• Keep the vent grille and intake areas clear of dust and grease.
• Use microwave-safe cookware and avoid running the unit empty.
• Close the door gently so the latch and switches stay aligned.
• If the unit goes dead or intermittently loses power, have the circuit and connections checked before replacing parts.

Common “end-of-life” symptoms and likely areas

Symptom	Common cause area	Example part on this model page
Runs but does not heat	High-voltage circuit	Diode W11256462 or magnetron circuit components
Dead display, no response	Fuse or power feed issue	Microwave fuse (W11707984)
Starts only when door is held or slammed	Door interlock/switch issue	Microwave door interlock switch W10269458
Poor venting over the range	Grease filter or airflow restriction	Microwave grease filter (W10208631A)

Why it matters

Knowing the typical 8 to 10 year lifespan helps you decide whether to maintain and repair your WMH73L20AS0 (often cost-effective for switch, filter, or lamp issues) or plan for replacement when major high-voltage parts fail.

You can order WMH73L20AS0 replacement parts from the parts list for this model, or search by model number on Sears PartsDirect.

Last updated: February 2026

To find the cooking wattage for your Whirlpool WMH73L20AS0 microwave/hood combo, we recommend checking the model and rating label (typically inside the door area) and confirming the exact wattage in the WMH73L20AS0 installation guide.

Where to look for the wattage

Check these common spots first:

• The rating label inside the microwave door opening (often on the frame or inner panel)
• The model and serial tag area near the door latch side
• The electrical specifications section in the WMH73L20AS0 installation guide
• Your home listing or appliance documentation packet (if you kept it)

What “wattage” can mean (quick comparison)

Microwaves have more than one wattage number; the one most people want is cooking power.

Wattage type	What it describes	Why you care
Cooking wattage (output power)	Heating performance	Determines cook times and how fast food heats
Input wattage (power draw)	Electricity the unit uses while running	Helps with electrical planning and circuit loading
Circuit requirement	Dedicated circuit and protection	Helps prevent nuisance trips and power issues

Why it matters

Cooking wattage affects real-world results. If you use cook times from recipes or packaged foods that assume a different wattage, you can end up with undercooked or overheated food. Knowing the correct wattage also helps when comparing performance across Whirlpool microwave/hood combo models.

If you are checking wattage because the microwave is not heating

If the unit runs but does not heat, wattage is not the issue; a failed high-voltage component or a door interlock problem is more likely. These model-matched parts are commonly involved:

• Diode W11256462 (high-voltage rectifier component)
• Capacitor W10850446 (high-voltage capacitor)
• Microwave magnetron W10245183 (primary heating component)
• Microwave door interlock switch W10269458 (safety switch that must close properly)

For ordering, you can use the parts list for WMH73L20AS0 or search by model number on Sears PartsDirect.

Last updated: February 2026

Common problems we see with Whirlpool microwaves like model WMH73L20AS0 include no power, not heating, door switch issues, turntable problems, and vent or light failures. Many symptoms trace back to power supply checks, door interlocks, or a failed high-voltage component; use the installation guide for safe electrical and grounding requirements.

Most common symptoms (and what they usually mean)

• Microwave is dead (no display, no response): tripped breaker, loose plug, or an internal fuse issue such as a failed microwave fuse W11707984.
• Runs but does not heat: high-voltage circuit problem (often the diode W11256462, capacitor, or magnetron).
• Starts then stops when you close the door or press Start: worn or misaligned door interlock switches such as microwave door interlock switch W10269458 or microwave door interlock switch W10269460.
• Turntable not rotating: coupler or drive issue such as the microwave turntable motor coupler W10435116.
• Vent fan is weak or noisy: grease buildup, blocked ducting, or airflow parts issues; a clogged grease filter like filter W10208631A is a common cause.
• Cooktop light not working: failed bulb or housing such as the lamp assembly 8206232A.

Quick checks we recommend first (safe, no disassembly)

• Confirm the unit is plugged into a grounded 3-prong outlet (no extension cord).
• Reset the household breaker or replace the household fuse if it is blown.
• Test heating with 1 cup of water for 1 minute at 100% power (a standard operational check).
• Clean or replace the grease filter and confirm the vent damper moves freely.
• Inspect the door for a firm close and consistent latch feel (a clue to interlock problems).

Common problems and likely parts (at a glance)

Problem you notice	Common cause category	Example part for WMH73L20AS0
No power	Power protection	Microwave fuse (W11707984)
No heat	High-voltage circuit	Diode (W11256462) or magnetron (W10245183)
Intermittent running	Door safety circuit	Door interlock switch (W10269458 / W10269460)
Poor venting	Airflow restriction	Grease filter (W10208631A)

Why it matters

Microwave/hood combos use door interlocks and high-voltage components to operate safely. If a door switch is failing or the unit is not properly grounded, you can get symptoms like no-start, random stopping, or blown fuses. Following the electrical and venting requirements in the installation guide helps prevent repeat failures.

For replacement parts specific to WMH73L20AS0, order from the parts list for this model or search by model number on Sears PartsDirect.

Last updated: February 2026