Question 1

the sensor cook functions keep overcooking my popcorn or melting my butter.

Accepted Answer

DIAGNOSIS The humidity sensor is being triggered incorrectly, often because you're using the wrong container or the room is too humid. FIX For popcorn, always use a microwave popcorn bag designed for sensor cooking. Place it centered on the flatbed. For 'Melt Butter', use a small, uncovered ceramic or glass dish with the butter in a single layer. IF THAT DIDN'T WORK Wipe the interior dry before using sensor cook. Ambient steam or moisture from a previous cook can fool the sensor. Also, never cover the dish with plastic wrap during a sensor function—it traps steam and causes overcooking. HEADS UP Sensor cooking is an estimate. Start with the minimum time suggested for your food and stop it manually if you hear popping slowing down (for popcorn) or see the butter is melted.

Question 2

food heats unevenly in this microwave, some parts are boiling and others are cold.

Accepted Answer

DIAGNOSIS This is a limitation of the fixed, non-rotating turntable design. The 'Smooth Wave' system still creates hotspots if food is not arranged properly. FIX Always use a round, shallow dish centered in the cavity. Stir or rearrange food halfway through cooking. For dense items like potatoes, arrange them in a circle, not a pile. IF THAT DIDN'T WORK Ensure you're not using metal-trimmed plates or bowls, which disrupt the wave pattern. Also, avoid overfilling the cavity—leave space for the waves to circulate. HEADS UP Don't assume it's broken. No microwave heats perfectly uniformly without stirring or a rotating turntable. This is a trade-off for the sleek, flatbed design.

Question 3

the clock on my breville microwave resets to 0:00 every time i unplug it, is the battery dead?

Accepted Answer

DIAGNOSIS Yes. The microwave has a small internal backup battery (typically a coin cell) that maintains the clock and settings during brief power outages. It's depleted. FIX This model doesn't have a user-replaceable clock battery. You'll need to live with resetting the clock after a power loss, or contact Breville support for a service option. IF THAT DIDN'T WORK If the clock resets even when the unit is plugged in and appears to have power, it indicates a deeper issue with the main control board, not just the backup battery. HEADS UP The clock resetting doesn't affect cooking performance. It's purely a convenience feature. Constantly unplugging and replugging to 'fix' it can stress the power components.

Question 4

how do i clean the inside roof of this microwave? it has that brown splatter and won't come off.

Accepted Answer

DIAGNOSIS The splatter is baked-on grease and food. The stainless steel interior can be cleaned, but the textured 'roof' around the light and vents is tricky. FIX Heat a bowl of water with a few tablespoons of white vinegar for 3-5 minutes until the cavity is steamy. Let it sit 5 minutes. Use a soft cloth or non-abrasive sponge with the warm vinegar water and a drop of dish soap to wipe. Avoid the metal grill of the vent. IF THAT DIDN'T WORK For stubborn spots, make a paste of baking soda and water. Apply it directly to the stain, let it sit for 15 minutes, then gently scrub with the soft sponge. HEADS UP Never use abrasive pads, steel wool, or harsh chemicals like oven cleaner. They will damage the stainless finish and can create fumes next time you cook.

Question 5

my smooth wave makes a loud humming or grinding noise when it runs, not the normal fan sound.

Accepted Answer

DIAGNOSIS The noise is almost certainly coming from the cooling fan. Debris has gotten into the fan blades or the fan motor bearings are failing. FIX Unplug the unit. Locate the rear ventilation grille. Use a vacuum cleaner with a brush attachment to thoroughly suck out any dust, pet hair, or crumbs from the exterior vents. IF THAT DIDN'T WORK If the noise persists, the internal fan may be misaligned or have a damaged blade. This requires removing the outer casing to inspect—a job for a technician, as you'll be near high-voltage components. HEADS UP Don't ignore a grinding fan. Overheating from inadequate cooling can damage the magnetron and other expensive parts.

Question 6

the control panel on my breville microwave is completely unresponsive, no lights, nothing.

Accepted Answer

DIAGNOSIS Total power failure. The most common cause is a tripped thermal fuse inside the unit or a loose power cord connection at the wall. FIX Check your kitchen circuit breaker or GFCI outlet first. Unplug the microwave from the wall, wait 60 seconds, then plug it firmly into a different, known-working outlet. Listen for a faint hum or click when you plug it in. IF THAT DIDN'T WORK If other outlets work, the microwave's internal thermal fuse may have blown due to overheating. This requires disassembly to check and replace—not a user-serviceable part. HEADS UP Don't repeatedly plug and unplug it trying to get a response. If it's completely dead on a good outlet, it needs professional diagnosis; attempting to bypass fuses is a fire hazard.

Question 7

why does my breville smooth wave smell like burning plastic when i use it?

Accepted Answer

DIAGNOSIS You're likely smelling overheated plastic from a foreign object inside the cavity or a packaging tag left on the unit. It's not the microwave itself burning. FIX Immediately unplug it. Do a thorough visual inspection inside the cavity and on the waveguide cover (the mica plate on the right wall). Look for melted plastic wrap, a twist-tie, a sticker, or any small object. IF THAT DIDN'T WORK If the cavity is clear, the smell could be coming from the vent system if it's new. Run it on high for 2 minutes with a bowl of water and lemon slices to clear manufacturing residues. Ensure nothing plastic is on the exterior vent slots. HEADS UP Never run it empty. If the burning smell persists after cleaning, stop using it—it could indicate a serious electrical fault requiring service.

Question 8

my breville smooth wave microwave just beeps three times and won't start cooking, what's the deal?

Accepted Answer

DIAGNOSIS The microwave is detecting the door isn't fully closed or the latch switch is failing. Three beeps is its standard 'door open' alert. FIX First, check the door is firmly shut—listen for a solid click. If it seems fine, inspect the door seal and latch area for any food debris blocking it. Wipe the inner door frame and latch clean with a damp cloth. IF THAT DIDN'T WORK The door latch microswitch might be faulty. Gently press the door latch mechanism with your finger while trying to start it. If it works with pressure, the switch is worn and needs professional replacement. HEADS UP Don't try to operate it if you suspect a faulty switch—the microwave won't run with the door 'ajar' for safety, but a failing switch can be intermittent and frustrating.

Breville Smooth Wave BMO850BSS Microwave

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