Quick answer: sparks mean stop the cycle, then look for metal, mess or damage
Microwave arcing is the technical name for sparks. It can damage the oven. Maytag says prolonged arcing can damage the appliance. Stop the cycle at the first flash. Then work from the cheapest cause to the costliest.
- Metal, foil, a twist tie or trim on a dish.
- Food or grease buildup inside.
- A rack or tray touching the walls.
- Running the oven empty.
- Chipped paint or coating inside the cavity.
- A burnt or damaged waveguide cover.
The first four are yours to fix in minutes. The last two need a technician.
Most likely causes of microwave sparking, ranked from cheapest to costliest
Metal, foil and metallic trim
Per Maytag, these can all spark:
- Crumpled foil or foil touching the walls.
- Metal cookware.
- Gold or silver rims.
- Skewers, twist ties and staples.
- Metallic glaze.
AEG says foil must stay at least 2 cm from the walls. It warns that recycled paper and newspaper may carry metal fragments. Remove the item and try again with a microwave-safe dish.
Food and grease buildup
Splatter can overheat and spark. Check the cover, turntable, rack supports, cavity walls and door frame. Maytag lists soil buildup as a main cause. LG says to clean spills right away and check the cavity for damage afterward. Wipe the inside, dry it and test again. Burnt-on residue that returns after cleaning points past a simple wipe.
A rack that touches the walls or misses its brackets
A metal rack must sit on all four of its plastic support brackets. LG says the plastic prevents sparking when the rack is installed correctly. A rack or crisping pan touching the walls, ceiling or floor can arc, per Maytag. Seat the rack properly or take it out. Damaged rack supports with exposed metal need replacing.
Microwave sparking with nothing metal inside
An empty oven can spark, because nothing absorbs the energy. So microwave sparking with nothing metal inside is still possible. LG says to put an 8 oz cup of water inside. Run a timed cook for 30 seconds. No sparks means the oven is fine to keep using. Dense vegetables can also spark because of their mineral content, per Maytag. Green beans, carrots and green peppers are examples.
Chipped paint or coating inside the cavity
Chipped interior paint can expose bare metal. Appliance Parts Pros lists it as a cause of arcing, along with debris and a damaged waveguide cover. LG goes further. If the cavity is damaged and arcing continues, stop using the microwave and schedule service. Do not touch up the spot with household paint. Call.
Microwave waveguide cover burnt or damaged
The waveguide cover sits inside the cavity and guards the opening where energy enters. Appliance Parts Pros says to look for cracks, burn marks or warping. Replace a damaged cover. A cover that is brown, blackened or loose is a repair job. Do not run the oven until it is fixed.
Safe checks to try before you use the microwave again
Do these with the oven unplugged and cool.
- Unplug the microwave and open the door.
- Remove every dish, tray, rack and utensil.
- Wipe the cavity, turntable, rack supports and door frame, and dry them.
- Seat the rack on all four plastic brackets, or leave it out.
- Look at the waveguide cover and interior paint for brown, black or chipped spots.
- Plug the unit back in and place an 8 oz cup of water inside. Run a timed 30 second cook.
No sparks and no new smell means the oven is fine to keep using, per LG. Sparks with only water inside mean stop, unplug and read the next section.
Signs you should stop and call a technician
- Sparks while only a cup of water is inside.
- Brown or black marks on the waveguide cover or the cavity wall.
- Chipped paint with bare metal showing.
- A burning smell that lingers after you wipe the inside.
- A door that does not close properly or is damaged. The FDA label rule in 21 CFR 1030.10 says not to operate an oven in that condition.
Never remove the outer casing. A microwave stores high voltage. Repair guides say to unplug the unit and discharge the capacitor before touching internal parts.
What a technician checks, and where repair stops making sense
The technician checks the waveguide cover, the cavity coating, the rack supports and the door. Then they test the electrical parts behind them, with the unit unplugged and discharged. A new waveguide cover or rack support is a modest repair. Cavity damage is different. A microwave repair visit may end with advice to replace.
Age matters. InterNACHI lists a microwave at about 9 years, as a guideline. A nine-year-old countertop with a damaged cavity is rarely worth fixing. An over-the-range or built-in unit often is.
Keeping sparks away: habits that protect the cavity
Wipe the inside after each use and deep clean weekly, as Maytag advises. Use only microwave-safe dishes. If your manual allows foil at all, keep it at least 2 cm from the walls. Skip recycled paper and newspaper. Cover food with a microwave-safe lid instead of a twist-tied bag.
Microwave sparking help in Las Cruces, NM
Washer Repair Las Cruces serves Las Cruces, NM. We send a local technician to check a sparking microwave. Our microwave repair page shows how a visit works. The communities we also serve are listed in one place. The homepage covers every appliance. Call (575) 266-8348. A person answers, and the estimate is free.
The July 2007 Sunbeam over-the-range microwave recall for internal arcing
Scene. On July 17, 2007, the CPSC announced recall 07-562, per the CPSC notice. It covered about 300 Sunbeam over-the-range microwaves, model SNM1501RAQ. They were sold with mobile homes in February and March 2007.
Problem. Electrical arcing inside the microwave could start a fire. No incidents or injuries were reported.
Tension. The firm was out of business. No repair or refund existed.
What We Did. We worked no Sunbeam job. A careful technician treats arcing as a stop sign. They unplug the unit and check the model label against recall lists.
Outcome. The notice told owners to discard the microwave. It said not to donate or resell it.
Lesson. Sparks are the warning, not the problem. When the cause cannot be fixed, replacing the unit is the safe answer.
Microwave sparking questions, answered
Is a sparking microwave dangerous?
It can be. Arcing can damage the oven. A 2007 recall covered over-the-range microwaves whose internal arcing could start a fire. Stop the cycle and unplug it at the first spark. If sparks return with only a cup of water inside, keep it off. Call a technician.
Why does my microwave spark with nothing metal in it?
Common reasons are food buildup, a rack touching the walls and an empty cavity. Chipped interior paint or a damaged waveguide cover can also cause it. LG says to test with an 8 oz cup of water for 30 seconds. If it still sparks, stop using the oven and have it checked.
Can I keep using a microwave that sparked once?
Yes, if you found a clear cause and the water test passes. A single spark from foil or a metal-rimmed plate is usually fixed. Remove the item and wipe the cavity. Repeated sparks, burn marks or chipped paint mean stop using it. Call for a repair.
What is the waveguide cover and why does it burn?
It is a small cover inside the cavity. It guards the opening where microwave energy enters. Food splatter and grease can build up on it and burn. Appliance Parts Pros says to replace one that is cracked, scorched or warped. A burnt cover should not be used.
Why does a metal rack make a microwave spark?
Yes, a metal rack can spark if it does not sit on all four plastic support brackets. The same goes for one that touches the cavity wall. Maytag and LG both warn about racks and crisping pans touching the walls. Reseat the rack correctly or leave it out, and replace damaged rack supports.
Is it worth repairing a sparking microwave?
It depends on the cause and the age. A waveguide cover or rack support is a modest repair. Cavity damage past the 9 year InterNACHI estimate often is not. Washer Repair Las Cruces in Las Cruces gives a free estimate. We say plainly when replacing the microwave makes more sense.
Does foil always make a microwave spark?
No. Small, smooth pieces of foil may be allowed, per AEG. Keep them at least 2 cm from the walls. Crumpled foil or foil touching the walls can arc. Foil containers are not recommended unless the manufacturer says so. Check your manual, and when in doubt, use a glass dish.
Who fixes a sparking microwave in Las Cruces?
Washer Repair Las Cruces sends local technicians to Las Cruces homes. You can call (575) 266-8348 to describe the sparks. A person answers, and the estimate is free. If the unit is not worth fixing, the technician says so before work starts. You decide with the facts.
Sparks that keep coming back in Las Cruces deserve a call
Tell us what you saw and what you tried, and you get a free estimate. Call (575) 266-8348. A person answers, with no obligation.
Call (575) 266-8348